Linux Unix Help SHIRISH SHUKLA

Setup SUSE Local Repository

2016-09-16T21:58:00.000-07:00

Description: There are many situation where internet access not available on server and it's being required to install packages as need with dependencies. The solution is simple to create local repository and publish to servers within network .

Here below are simple minimal steps required to setup a local repository on SUSE operating system

Steps :

1. Mount iso/dvd

mount /dev/cdrom/ /mnt

2. Disable all existing repos

zypper mr -d -a

3. Set enable DVD repo temporary

zypper ar dir:///mnt/ OpensuseDVD

4. Install createrepo

zypper -n install createrepo

5. Install apache

zypper -n install apache2

6. Copy rpms

mkdir -p /srv/www/myrepo/Suse13

rsync -avp /mnt/suse/ /srv/www/myrepo/Suse13/

#copy gpg keys

cp -rp /mnt/gpg-pubkey-* /srv/www/myrepo/Suse13/

7. Create apache config for repo

# cat /etc/apache2/conf.d/mrepo.conf

Alias /repo /srv/www/myrepo/

Options Indexes FollowSymlinks SymLinksifOwnerMatch IncludesNOEXEC

IndexOptions NameWidth=* DescriptionWidth=*

AllowOverride None

Order deny,allow

Allow from all

</Directory>

8. Restart/reload enable apache2

rcapache2 start

chkconfig -a apache2

9. Createrepo "It will take bit time .."

createrepo -v /srv/www/myrepo/Suse13/

Spawning worker 0 with 5187 pkgs

Workers Finished

Gathering worker results

Saving Primary metadata

Saving file lists metadata

Saving other metadata

Generating sqlite DBs

Sqlite DBs complete

#Validate

ls -l /srv/www/myrepo/Suse13/repodata/

10. Add Repo (ar)

#zypper addrepo -t <repository type> <path> <repository name>

zypper addrepo -t YUM http://192.168.8.110/repo/Suse13/ SLES13.2

# Test "First time run ask to assign repo metadata"

zypper se test

File 'repomd.xml' from repository 'SLES13.2' is unsigned, continue? [yes/no] (no): yes

Building repository 'SLES13.2' cache ......................

...

#Change priority

zypper mr -p 1 SUSE13.2

#Verify

zypper lr SUSE13.2

#Validate repo config file
vi /etc/zypp/repos.d/SLES13.2.repo

[SUSE13.2]

name=SLES13.2

baseurl=http://192.168.8.110/repo/Suse13/

enabled=1

autorefresh=0

type=rpm-md

priority=1 # 0-99, 0 -higher

#Added below this line gpg keys

gpgcheck=1

gpgkey=http://192.168.8.110/repo/Suse13/gpg-pubkey-3dbdc284-4be1884d.asc,http://192.168.8.110/repo/Suse13/gpg-pubkey-307e3d54-4be01a65.asc

11. View repositry detials

# zypper lr SUSE13.2

Alias : SUSE13.2

Name : SLES13.2

URI : http://192.168.8.110/repo/Suse13/

Enabled : Yes

Priority : 1

Auto-refresh : Off

Keep Packages : Off

Type : rpm-md

GPG Check : On

GPG Key URI : http://192.168.8.110/repo/Suse13/gpg-pubkey-3dbdc284-4be1884d.asc,http://192.168.8.110/repo/Suse13/gpg-pubkey-307e3d54-4be01a65.asc

Path Prefix :

Parent Service :

MD Cache Path : /var/cache/zypp/raw/SUSE13.2

12. Install a package
zypper install nmap

Keyword/TAG: SUSE 13.2, Local, Repository, http, apache2

System Authentication via LDAP server

2013-09-20T03:11:00.001-07:00

Getting Linux to authenticate via LDAP

Today various modes are there to authenticate system devices such as AD(Microsoft active directory) and AAA but LDAP (Light weight directory access protocol) is kind of protocol have it's unique place which use it's own database to authenticate various services applications such as mail, squid, samba, webpages servers and various network devices .

Here we are going to configure ldap server and Linux (centOs 5.7) client for user authentication from LDAP server .

These steps help you to configure Ldap server to act as centralized authentication server for your Linux/Unix servers .

Eg:
Server: server.shirish.com (192.168.8.10)
Client : client.shirish.com (192.168.8.20)

Prerequisite :

1. Proper communication and required ports opens between client and server (default ports : 389 and ssh 22 )

2. Assuming you have proper DNS resolver

3. Yum server configured to install necessary packages .

Do following seps at LDAP server: server.shirish.com end

Steps:

1. Installing Openldap on Linux server (ie.LDAP server)

Login to server : server.shirish.com as root and install following packages .

Required Packages to be installed .

openldap

openldap-clients

openldap-devel

openldap-servers

nss_ldap

[root@server1 ~]# yum -y install openldap*
Loaded plugins: fastestmirror
Loading mirror speeds from cached hostfile
Setting up Install Process
Package openldap-2.3.43-12.el5_6.7.i386 already installed and latest version
Resolving Dependencies
--> Running transaction check
---> Package openldap-clients.i386 0:2.3.43-12.el5_6.7 set to be updated
---> Package openldap-devel.i386 0:2.3.43-12.el5_6.7 set to be updated
--> Processing Dependency: cyrus-sasl-devel >= 2.1 for package: openldap-devel
---> Package openldap-servers.i386 0:2.3.43-12.el5_6.7 set to be updated

[root@server1 CentOS]# cd /etc/openldap/
[root@server1 openldap]# pwd
/etc/openldap
[root@server1 openldap]#
[root@server1 openldap]# ls -lrt
total 28
-rw-r----- 1 root ldap 921 Mar 31 2011 DB_CONFIG.example
-rw-r----- 1 root ldap 3799 Mar 31 2011 slapd.conf
-rw-r--r-- 1 root root 246 Mar 31 2011 ldap.conf
drwxr-xr-x 2 root root 4096 Mar 31 2011 cacerts
drwxr-xr-x 3 root root 4096 Aug 17 12:05 schema
[root@server1 openldap]#

2. Create Password for LDAP admin

have to copy this encrypted password in slapd.conf file)

[root@server1 openldap]# slappasswd
New password:
Re-enter new password:
{SSHA}p+IMM8pNWzGirnHTizlpc2IwSrc6rgXR

[root@server1 openldap]#

3.Now add/change following lines in your /etc/openldap/slapd.conf file .

include         /etc/openldap/schema/core.schema
include         /etc/openldap/schema/cosine.schema
include         /etc/openldap/schema/inetorgperson.schema
include         /etc/openldap/schema/nis.schema
include         /etc/openldap/schema/redhat/autofs.schema
allow bind_v2
pidfile         /var/run/openldap/slapd.pid
argsfile        /var/run/openldap/slapd.args
database        bdb
suffix          "dc=shirishlinux,dc=com"
rootdn          "cn=admin,dc=shirishlinux,dc=com"
password-hash {CRYPT}
rootpw {SSHA}p+IMM8pNWzGirnHTizlpc2IwSrc6rgXR

directory       /var/lib/ldap
index objectClass                       eq,pres
index ou,cn,mail,surname,givenname      eq,pres,sub
index uidNumber,gidNumber,loginShell    eq,pres
index uid,memberUid                     eq,pres,sub
index nisMapName,nisMapEntry            eq,pres,sub

Verify above your changes by ..

[root@server1 openldap]# egrep -v "^#|^$" /etc/openldap/slapd.conf

3. Now copy /etc/openldap/DB_CONFIG.example file to /var/lib/ldap/DB_CONFIG directory

[root@server1 openldap]# cd /etc/openldap/

[root@server1 openldap]# cp -rp DB_CONFIG.example /var/lib/ldap/DB_CONFIG
[root@server1 openldap]# ls -ld /var/lib/ldap/ <-- Make sure your ldap directory permission .
drwx------ 2 ldap ldap 4096 Aug 17 12:22 /var/lib/ldap/
[root@server1 openldap]# ls -ld /var/lib/ldap/DB_CONFIG
-rw-r----- 1 root ldap 921 Mar 31 2011 /var/lib/ldap/DB_CONFIG
[root@server1 openldap]#
[root@server1 openldap]# chown ldap:ldap /var/lib/ldap/DB_CONFIG
[root@server1 openldap]# chmod 600 /var/lib/ldap/DB_CONFIG

Now start ldap service

[root@server1 openldap]# /etc/init.d/ldap start
Checking configuration files for slapd: config file testing succeeded
[ OK ]
Starting slapd: [ OK ]
[root@server1 openldap]#

Now we have to create base schema to understand our domain communicate input and request t ldap server .

There are various way to create it, but easiest way which admin prefer is migrate scripts available at path "/usr/share/openldap/migration"

[root@server1 openldap]# cd /usr/share/openldap/migration
[root@server1 migration]# ls -rlt migrate_common.ph
-rw-r--r-- 1 root root 8880 Mar 31 2011 migrate_common.ph

Take backup of this script .
[root@server1 migration]# cp -rp migrate_common.ph migrate_common.ph_back

This script is made for domain "padl.com" which now we have to change for our "shirishlinux.com" domain as below before running this script .

[root@server1 migration]# grep -i padl migrate_common.ph
$DEFAULT_MAIL_DOMAIN = "padl.com";
$DEFAULT_BASE = "dc=padl,dc=com";
#define(`confLDAP_DEFAULT_SPEC',`-h "ldap.padl.com"')dnl
# $DEFAULT_MAIL_HOST = "mail.padl.com";
[root@server1 migration]#

We will do this changes by sed, but you can do by opening file via "vi" editor too .
First check :
[root@server1 migration]# sed "s/padl/shirishlinux/g" migrate_common.ph | grep -i shirish
$DEFAULT_MAIL_DOMAIN = "shirishlinux.com";
$DEFAULT_BASE = "dc=shirishlinux,dc=com";
#define(`confLDAP_DEFAULT_SPEC',`-h "ldap.shirishlinux.com"')dnl
# $DEFAULT_MAIL_HOST = "mail.shirishlinux.com";
[root@server1 migration]#

Above seems okay, now will implement changes using sed as below .

[root@server1 migration]# sed -i "s/padl/shirishlinux/g" migrate_common.ph

Verify Now ....
[root@server1 migration]# grep -i shirishlinux migrate_common.ph
$DEFAULT_MAIL_DOMAIN = "shirishlinux.com";
$DEFAULT_BASE = "dc=shirishlinux,dc=com";
#define(`confLDAP_DEFAULT_SPEC',`-h "ldap.shirishlinux.com"')dnl
# $DEFAULT_MAIL_HOST = "mail.shirishlinux.com";
[root@server1 migration]#

The above seems fine, as per our requirement .

Now we will create structure base schema for ldap database using this script as below .

[root@server1 migration]# mkdir /root/LDAP

[root@server1 migration]# ./migrate_base.pl > /root/LDAP/base.ldif

Now just look ad base.ldif schema file, will get bit idea about it by looking at various fields of this .

[root@server1 migration]# cat /root/LDAP/base.ldif
dn: dc=shirishlinux,dc=com
dc: shirishlinux
objectClass: top
objectClass: domain

dn: ou=Hosts,dc=shirishlinux,dc=com
ou: Hosts
objectClass: top
objectClass: organizationalUnit

dn: ou=Rpc,dc=shirishlinux,dc=com
ou: Rpc
objectClass: top
objectClass: organizationalUnit

dn: ou=Services,dc=shirishlinux,dc=com
ou: Services
objectClass: top
objectClass: organizationalUnit

dn: nisMapName=netgroup.byuser,dc=shirishlinux,dc=com
nismapname: netgroup.byuser
objectClass: top
objectClass: nisMap

dn: ou=Mounts,dc=shirishlinux,dc=com
ou: Mounts
objectClass: top
objectClass: organizationalUnit

dn: ou=Networks,dc=shirishlinux,dc=com
ou: Networks
objectClass: top
objectClass: organizationalUnit

dn: ou=People,dc=shirishlinux,dc=com
ou: People
objectClass: top
objectClass: organizationalUnit

dn: ou=Group,dc=shirishlinux,dc=com
ou: Group
objectClass: top
objectClass: organizationalUnit

dn: ou=Netgroup,dc=shirishlinux,dc=com
ou: Netgroup
objectClass: top
objectClass: organizationalUnit

dn: ou=Protocols,dc=shirishlinux,dc=com
ou: Protocols
objectClass: top
objectClass: organizationalUnit

dn: ou=Aliases,dc=shirishlinux,dc=com
ou: Aliases
objectClass: top
objectClass: organizationalUnit

dn: nisMapName=netgroup.byhost,dc=shirishlinux,dc=com
nismapname: netgroup.byhost
objectClass: top
objectClass: nisMap

Now we will add this ldif file to LDAP database by using ldapadd command .
Here..
-X   Authzid SASL authorization identity ("dn:<dn>" or "u:<user>")
-x   Simple authentication
-W  Prompt for bind password
-D   Binddn bind DN
-f    File read operations from `file'

[root@server1 migration]# ldapadd -x -D "cn=admin,dc=shirishlinux,dc=com" -W -f /root/LDAP/base.ldif
Enter LDAP Password:
adding new entry "dc=shirishlinux,dc=com"
adding new entry "ou=Hosts,dc=shirishlinux,dc=com"
adding new entry "ou=Rpc,dc=shirishlinux,dc=com"
adding new entry "ou=Services,dc=shirishlinux,dc=com"
adding new entry "nisMapName=netgroup.byuser,dc=shirishlinux,dc=com"
adding new entry "ou=Mounts,dc=shirishlinux,dc=com"
adding new entry "ou=Networks,dc=shirishlinux,dc=com"
adding new entry "ou=People,dc=shirishlinux,dc=com"
adding new entry "ou=Group,dc=shirishlinux,dc=com"
adding new entry "ou=Netgroup,dc=shirishlinux,dc=com"
adding new entry "ou=Protocols,dc=shirishlinux,dc=com"
adding new entry "ou=Aliases,dc=shirishlinux,dc=com"
adding new entry "nisMapName=netgroup.byhost,dc=shirishlinux,dc=com"
[root@server1 migration]#

Now it's time to create user and add same in ldap database .
1. Create a normal user on ldap server say ldapuser

[root@server1 migration]# useradd ldapuser
[root@server1 migration]# passwd ldapuser
Changing password for user ldapuser.
New UNIX password:
BAD PASSWORD: it is WAY too short
Retype new UNIX password:
passwd: all authentication tokens updated successfully.
[root@server1 migration]#

[root@server1 migration]# getent passwd ldapuser
ldapuser:x:505:506::/home/ldapuser:/bin/bash
[root@server1 migration]#

/usr/share/openldap/migration/migrate_passwd.pl [root@server1 migration]# grep -i ldapuser /etc/passwdldapuser:x:505:506::/home/ldapuser:/bin/bash
[root@server1 migration]#

[root@server1 migration]# grep -i ldapuser /etc/passwd > /root/LDAP/ldapuser_u

Note: Here we are using default home for user, but problem is when user with same name exit's on client server, so it's better to avoid such situation .
Later in this blog will see how to export NFS home directory for each user, which get's auto mounted upon user login .

Now migrate this ldif file with migration script"
/usr/share/openldap/migration/migrate_passwd.pl" as below .

[root@server1 migration]# /usr/share/openldap/migration/migrate_passwd.pl   /root/LDAP/ldapuser_u /root/LDAP/ldapuser_u.ldif
[root@server1 migration]#

[root@server1 migration]# cat /root/LDAP/ldapuser_u.ldif
dn: uid=ldapuser,ou=People,dc=shirishlinux,dc=com
uid: ldapuser
cn: ldapuser
objectClass: account
objectClass: posixAccount
objectClass: top
objectClass: shadowAccount
userPassword: {crypt}$1$DxsQboOW$m56cO.1e/LDOaWznHD3ll/
shadowLastChange: 15968
shadowMin: 0
shadowMax: 99999
shadowWarning: 7
loginShell: /bin/bash
uidNumber: 505
gidNumber: 506
homeDirectory: /home/ldapuser
[root@server1 migration]#

Similarly we will do for group file entry as below of the user "ldapuser"

[root@server1 migration]# grep -i ldapuser /etc/group > /root/LDAP/ldapuser_g
[root@server1 migration]# cat /root/LDAP/ldapuser_g
ldapuser:x:506:
[root@server1 migration]#
[root@server1 migration]# /usr/share/openldap/migration/migrate_group.pl /root/LDAP/ldapuser_g /root/LDAP/ldapuser_g.ldif
[root@server1 migration]#
[root@server1 migration]# cat /root/LDAP/ldapuser_g.ldif
dn: cn=ldapuser,ou=Group,dc=shirishlinux,dc=com
objectClass: posixGroup
objectClass: top
cn: ldapuser
userPassword: {crypt}x
gidNumber: 506

Now we will add this ldif file too to ldap database, similarly as we did for base.ldif file as below .

[root@server1 migration]# ldapadd -x -D "cn=admin,dc=shirishlinux,dc=com" -W -f /root/LDAP/ldapuser_u.ldif
Enter LDAP Password:
adding new entry "uid=ldapuser,ou=People,dc=shirishlinux,dc=com"
[root@server1 migration]# ldapadd -x -D "cn=admin,dc=shirishlinux,dc=com" -W -f /root/LDAP/ldapuser_g.ldif
Enter LDAP Password:
adding new entry "cn=ldapuser,ou=Group,dc=shirishlinux,dc=com"
[root@server1 migration]#

Now will verify our above entry in ldap database using ldapsearch command

[root@server1 migration]# ldapsearch -x -b 'dc=shirishlinux,dc=com' '(cn=ldapuser)'
# extended LDIF
#
# LDAPv3
# base <dc=shirishlinux,dc=com> with scope subtree
# filter: (cn=ldapuser)
# requesting: ALL
#
# ldapuser, People, shirishlinux.com
dn: uid=ldapuser,ou=People,dc=shirishlinux,dc=com
uid: ldapuser
cn: ldapuser
objectClass: account
objectClass: posixAccount
objectClass: top
objectClass: shadowAccount
userPassword:: e2NyeXB0fSQxJER4c1Fib09XJG01NmNPLjFlL0xET2FXem5IRDNsbC8=
shadowLastChange: 15968
shadowMin: 0
shadowMax: 99999
shadowWarning: 7
loginShell: /bin/bash
uidNumber: 505
gidNumber: 506
homeDirectory: /home/ldapuser
# ldapuser, Group, shirishlinux.com
dn: cn=ldapuser,ou=Group,dc=shirishlinux,dc=com
objectClass: posixGroup
objectClass: top
cn: ldapuser
userPassword:: e2NyeXB0fXg=
gidNumber: 506
# search result
search: 2
result: 0 Success
# numResponses: 3
# numEntries: 2
[root@server1 migration]#

Now we have done with ldap server end.. now at client server: client.shirish.com

Note: here am doing each communication via IP address, you can do using either ip/hostname which you prefer, but ensure hostname is getting resolve by your DNS server or have proper entry in /etc/hosts file .

Now will configure client server for the login authentication from our ldap server : server.shirish.com(192.168.8.10)

Install required packages using yum .

[root@server2 ~]# yum -y install openldap openldap-clients openldap-devel nss_ldap

CLI way: manually add/modify /etc/ldap.conf with below entries

base dc=shirishlinux,dc=com
uri ldap://192.168.8.10/

Add/Modify /etc/nsswitch.conf with below entries

passwd:     files ldap
shadow:     files ldap
group:      files ldap
netgroup:   nisplus ldap

GUI_WAY: Run authconfig-tui from CLI as below .

[root@client ~]# authconfig-tui

[root@server2 ~]# id ldapuser
uid=505(ldapuser) gid=506(ldapuser) groups=506(ldapuser)
[root@server2 ~]#

Good Congratulation!!! :) now user : ldapuser is logged in on client system.
BUT 1. Here user is not able to create any file and does not have any home directory for him .

So we will create home for user and try again login .

Great wow, it works... but ..but .. what if there are 1000 servers and 100 users, it will be tough task for admin to perform such steps for all users on all servers ..
Here below are solutions for same .

1. NFS shared home for each user, which will get auto mounted upon login
2. Upon user login, his home directory and other files get auto created locally on respective servers .

Above I will cover in coming blog .. keep learning .. have a great day .

--Shirish Shukla

Script to print partition utilization - HP-UX

2013-09-20T00:00:00.000-07:00

In HP-UX admin always want to have disk utilization output in Linux native format as "df- h"

Here the small script which format and give bdf output as "df -h"

In HP-UX, the bdf command display partition details in KB, so here's script that will display partition details in MB .

# vi bdff

################################
# Shirish Shukla
# Script to print partition utilization
################################
# Script to print Disk UTIL
if [ -z "$1" ]
then
df -Pk |egrep -v "Filesystem" | awk 'BEGIN { print " -Filesystem-\t\t -Total(MB)-\t-used(MB)-\t-avail(MB)-   -%used-\t-Mounted on-"} {print " " $1 "   \t " $2/1024 " \t" $3/1024 "    \t" $4/1024 " \t" $5 " \t" $6 }'
else
   a=$1
df -Pk |egrep -v "Filesystem" | awk 'BEGIN { print " -Filesystem-\t\t -Total(MB)-\t-used(MB)-\t-avail(MB)-   -%used-\t-Mounted on-"} {print " " $1 "   \t " $2/1024 " \t" $3/1024 "   \t" $4/1024 " \t" $5 " \t" $6 }' | egrep -i "filesystem|$a"
fi

# chmod 755 bdff
# mv bdff /usr/bin/bdff

# bdff

Create filesystem in a partition

2012-05-14T10:39:00.002-07:00

One of my application creates un-necessary logs or dumps that fills my filesystem .
Say example I have only root partition "/" and other filesystems(/var/, /usr etc..) are in "/" .
Sometime one of my application creates lots of files and unwaned logs at path /var/log/mycore and that fills my root partition and my oher application stops working .

I want to give a permanent solution, but I have some limitations as below
- I don't have extra free disk block to create new partition
- I can't add any any new disk/LUN etc .
- I can't stop that application logging etc...

Here's solution that have applied on one of my server and it's working as am expected .

## Example

# df -h /
Filesystem Size Used Avail Use% Mounted on
/dev/sda3 72G 57G 12G 79% /

## I have 12 GB free space now check size of dir: /var/log/mycore

# du -sch /var/log/mycore
2G /var/log/mycore
2G total

## Okay now we have 2 way
1> Define quota .. but not preferred .
2> Create a filesystem with allocated space

## Am preferring to go with way-2 as below
As have 12G free space on "/", so I will allocate 3GB to /var/log/mycore as below

Step-1: Create a file usign dd with size 3GB
# dd if=/dev/zero of=/var/log/FS_mycore bs=1024M count=3

Step-2: Create file system as per your requirement here am going with ext4
# mkfs.ext4 /var/log/FS_mycore

Step-3: Stop your application

Step-4: Move /var/log/mycore and create a new directory (Note: Reserve the permissions as original dir has)
# mv /var/log/mycore /var/log/mycore_old
# mkdir /var/log/mycore

Step-5: Mount and copy back all files and delete /var/log/mycore_old
# mount -o loop /var/log/FS_mycore /var/log/mycore
# mount -l

# df -h /var/log/mycore/
Filesystem            Size Used Avail Use% Mounted on
/var/log/FS_mycore    3.0G   68M 2.8G   2% /var/log/mycore/

# cp -rp /var/log/mycore_old/* /var/log/mycore/

# cd /var/log/mycore/ ; ls -lrth
# rm -fr /var/log/mycore_old/

## Make entry in fstab
/var/log/mycore_old     /var/log/mycore         ext4    defaults,loop        0 0

## Testing

# umount /var/log/FS_mycore # mount -a
# mount -l

## Step-6: Don't forget to start your application and check logs and all to verify all are okay ...

> Shirish Shukla

Diff file1 file2

2012-05-14T09:11:00.002-07:00

Many time we come across situation that we want exact diff between two files ..
There are various Linux command which we can use like

# diff
# cmp

EG:
# cat 1
1
2
3
4
5
6
# cat 2
2
3
6
7
8

### Using diff
# diff -iw 1 2
1d0
< 1
4,5d2
< 4
< 5
6a4,5
> 7
> 8

Expln:
1d0< 1
- Add "1" at line 1 of file 2
4,5d2
< 4
< 5
- Add "4" at line 4 of file 2
- Add "5" at line 5 of file 2
6a4,5
> 7
> 8
- Add "7" at line 7 of file 2
- Add "8" at line 8 of file 2

-- Actual count as line 0 - N

Here it's tough to found whats mean of above if you are using it first time, What we expect is I want only those line which are missing in file 2 .

So have written a small PerlScript to achieve so, it's possible with BashScript too, but to parse a large file BashScript will take more time .

Script : diff.pl

#!/usr/bin/perl
# Written By - Shirish
#### perl diff.pl file1 file2 OUTPUT
#### Will give you exact diff between file1 and file2 in OUTPUT file
##### Only lines that are in file1 but missing in file2
#################
#open a, "<filea";
#open b, "<fileb";
$x = $ARGV[0];
$y = $ARGV[1];
$z = $ARGV[2];
open a, "< $x";
open b, "< $y";
open (OP, ">$z") || die ("Unable to create Report");
local $/;
my @a = split /\n/, <a>;
my @b = split /\n/, <b>;
my %b = map { $_ => 1 } @b; # Make hash of B
my @res = grep { !defined $b{$_} } @a; # Everything in A not in B
print OP join "\n", @res;
#print join "\n", @res;
print "\n";

## How to use

## What's in file 1 which are absent in file 2
# perl diff.pl 1 2 1-2
# cat 1-2
1
4
5

## What's in file 2 which are absent in file 1
# perl diff.pl 2 1 2-1
# cat 2-1
7
8

> Shirish Shukla

ConverT Shell Script to C - Binary [executable ]

2012-03-20T06:32:00.003-07:00

Xxxxxxxxxxxxxx ConverT Shell Script to C - Binary [executable ] xxxxxxxxxxxxxxX

Hi many times we required to convert our script to be executable might be any of below reasons .

- We don't want to share our script code
- We want to set suid, guid that we can't do with shell scripts
- Want to run script without any extension as ./script.sh OR sh script.sh etc...

Here an fantastic toll that will hep you to achieve so .

Download & Install

rpmfind
Red Hat Linux el3 i386
Red Hat Linux el3 x86_64
Red Hat Linux el2.1 i386
CentOS-shc index

Note: Install proper Linux/Unix flavor rpm and architecture else it will not going to work as expected

Download:

# cat /etc/redhat-release
Red Hat Enterprise Linux ES release 3 (Taroon)
# uname -i
i386

### So have downloaded right rpm for CentOS-6
# wget http://pkgs.repoforge.org/shc/shc-3.8.6-1.el3.rf.i386.rpm

Install:

# cd   /rpms/shc/
# rpm -ivh shc-3.8.6-1.el3.rf.i386.rpm
warning: shc-3.8.6-1.el3.rf.i386.rpm: V3 DSA signature: NOKEY, key ID 6b8d79e6
Preparing...                ########################################### [100%]
   1:shc                    ########################################### [100%]

Write your script

AM taking example of expire-date.sh

Convert to executable c binary

# cd /myscripts; ls -lrt expire-date.sh
-rwxr-xr-x 1 root root 599 Mar 20 18:25 expire-date.sh

## Conver to exe using shc

# shc -f expire-date.sh
# gcc -o getexpiredt expire-pwd-date.sh.x.c
# mv getexpiredt /bin/ <<-- As per your requirement

## Now test

# file getexpiredt
getexpiredt: ELF 32-bit LSB executable, Intel 80386, version 1 (SYSV), for GNU/Linux 2.2.5, dynamically linked (uses shared libs), not stripped

## Execute

# getexpiredt
Enter Password Date [ DD:MM:YYYY EG: 25:02:2012] Format
                                                     DD: 01
                                                     MM: 02
                                                     YY: 2012
YOUR Password Will Expire on : Tue 1-May-2012
##

Have a fun ... Now remove your C code and sh code .

# rm -fr expire-pwd-date.sh*

--Shirish Shukla

Script to calculate Expiry Date

2012-03-20T05:32:00.003-07:00

Xxxxxxxxxxxxxxxxxx Script To Calculate Your Expiry Date xxxxxxxxxxxxxxxX

Most of the time we require to calculate when my password/licence will expire ... this below for what i required by all users to calculate when there password get expire ..on unix ..

You need to provide input as DD : MM : YYYY .

File: expire-date.sh

#!/bin/bash

### Calculate Expire Date

### By- Shirish Shukla

############## Hardcoded

ExpireDays=90

Hours=00;Mins=00;Secs=0;zxone=IST

##############

echo -en "Enter Password Date [ DD:MM:YYYY EG: 25:02:2012] Format \n"

echo -en "\t\t\t\t\t\t DD: " ; read dtys;

echo -en "\t\t\t\t\t\t MM: " ; read mms;

echo -en "\t\t\t\t\t\t YY: " ; read yys ;

############## Logic

EXPDT=$(date --date="$yys-$mms-$dtys $Hours:$Mins:$Secs $zxone + $ExpireDays days")

echo -en "\E[33m \n\nYOUR Password Will Expire on : " ; echo -en "\E[36m$EXPDT" | awk '{print $1 " "$3 "-" $2 "-" $NF}'

echo -en "\e[0m\n"

## How to USE

# sh expire-date.sh

Enter Password Date [ DD:MM:YYYY EG: 25:02:2012] Format

DD: 02

MM: 02

YY: 2012

YOUR Password Will Expire on : Wed 2-May-2012

Now I need to convert it into Binary Like I don;t want to Give same as to my users ... I can help you with this with my below Page ..

### Convert shell script to C binary .exe (executable)

--Shirish Shukla

HP-UX Basic Admin -3 - Software and imp log files

2012-03-12T08:21:00.002-07:00

Xxxxxxxxxxxxxx HP-UX - Basic Administration - III xxxxxxxxxxxxxxxxxxxxX
------------ Index -----------------
1> System Info
2> Basic Admins
3> Software and imp log files
4> Patching and Recovery          <Yet to update>
5> Backup and Tools              <Yet to update>
5> Advanced Administrations     <Yet to update>
------------------------------------

### Installed Softwares
# swlist -l product
# swlist -l patch
# swlist -l file
# swlist -l product | grep -i <ur-pack>

## verify package/patches
# swlist -l -a state
# swverify
# swlist -s   <path-of-your-pack>

### Install
# swinstall -s <path-of-your-pack>
>>>> Select Package -> Go to Action > Install ...

## Varify is Installed
# swlist -l product | grep -i <your-pack-name>

### Un-install
swremove
##

##### Important Files/log files etc..
### Log Files
# more /var/adm/syslog/syslog.log
# more /var/adm/syslog/mail.log
# more /var/adm/cron/log
# more /var/adm/syslog/syslog.log
# more /var/sam/log/samlog

--Shirish Shukla

HP-UX Basic Admin -2 - Basic Admins

2012-03-12T08:13:00.002-07:00

Xxxxxxxxxxxxxx HP-UX - Basic Administration - II xxxxxxxxxxxxxxxxxxxxX
------------ Index -----------------
1> System Info
2> Basic Admins
3> Software and imp log files
4> Patching and Recovery          <Yet to update>
5> Backup and Tools              <Yet to update>
5> Advanced Administrations     <Yet to update>
------------------------------------

## Display Hostname
# hostname

## IP Address
# netstat -ani

## Disk Utilization
# bdf
# df -Pk

## Show run levels
# who -r
   .       run-level 3 Oct 28 11:22    3    0    S
[[ 0: shut down
s,S: single-user
1: sys admin
2: multiuser
3*: share NFS
4*: start GUI
5: user-defined
6: user-defined ]]

### Shutdown/Restart
<<HALT>>
# shutdown -h -y now
# init 0
# shutdown -hy 120
# shutdown -h -y 120                   <<Shutdown in 120 sec>>
# shutdown -Fr now                     <Force fsck upon reboot SAFE way>

<<Reboot>>
# shutdown -r -y now
# shutdown -r 0
# reboot 0

<<To shutdown to single user mod>>
# shutdown -y 0
# shutdown -y now
# shutdown 0
# init 1
# hpux -is
# init S
# reboot -h    <<Come from Single user Mode>>

### LAN IP Info
# lanscan
# lanscan -v
# netstat -in
# ifconfig lanx   [ x=0/1/2/....]

Note: lanscan is deprecated in 11.31 now can find # nwmgr

### Assign/Display IP
## GET
# ifconfig lan0
# netstat -ani
#

## Set
# landiag
# lanadmin
# vi /etc/rc.config.d/netconf
HOSTNAME="Shirish"
INTERFACE_NAME[0]=lan0
IP_ADDRESS[0]=192.168.8.10
SUBNET_MASK[0]=255.255.255.0
BROADCAST_ADDRESS[0]=""
INTERFACE_STATE[0]=""
DHCP_ENABLE[0]=0
INTERFACE_MODULES[0]=""

##NOTE: Above required restart to take effects FOR immediate use below but note it's temp
# ifconfig lan3 192.168.8.10 netmask 255.255.255.0 up

## Up network interface
# ifconfig lan3 up

## Down network interactive
# ifconfig lan3 down

## ARP/Routing Table info/Define new route
# arp -a
# netstat -ar
# route add default 192.168.8.1 1

## Start/Stop Network
/sbin/init.d/net stop; /sbin/init.d/net start
Note: There's NO restart option you have to stop; then start
WARNING: Pass both as single command as above else you will loose control of your server/system

### Hostname start/stop
# /sbin/init.d/hostname stop
/sbin/init.d/hostname start

## Set timezone
# vi /etc/TIMEZONE

--Shirish Shukla

HP-UX Basic Admin -1 - Sys Info

2012-03-12T08:10:00.005-07:00

Xxxxxxxxxxxxxx HP-UX - Basic Administration - I xxxxxxxxxxxxxxxxxxxxX
------------ Index -----------------
1> System Info
2> Basic Admins
3> Software and imp log files
4> Patching and Recovery          <Yet to update>
5> Backup and Tools              <Yet to update>
5> Advanced Administrations     <Yet to update>
------------------------------------

## 64 or 32 bit ??
# getconf KERNEL_BITS
64

# file /stand/vmunix
/stand/vmunix: ELF-64 executable object file - PA-RISC 2.0 (LP64)

# find / -name print_mani*
/opt/ignite/binpa/print_manifest
# /opt/ignite/binpa/./print_manifest | grep -i mod
    Model:              9000/800/L3000-8x
    OS mode:            64 bit

# getconf HW_CPU_SUPP_BITS
64

## Get detailed information about System
# find / -name print_mani*
/opt/ignite/binpa/print_manifest
# /opt/ignite/binpa/./print_manifest

## Get Model
# model
9000/800/L3000-7x
### Configuration files
# cd /etc/rc.config.d

### Your Kernel
# cd /stand/vmunix

### Display Kernel Paramiters
# kctune
# sysdef
# kmtune

## Get memory info
# /usr/sam/lbin/./getmem
# dmesg | grep -i Phy
# /opt/ignite/bin/print_manifest    <-- An detailed infor about your system

### All Kernel Parms and Hwrs
# /usr/sbin/sysdef or ioscan –fn

### Devices Messages
# dmesg

## Get System Serial Number
# echo "sel dev 1 ;info;wait;infolog" | cstm |grep -i "System Serial Number"
   System Serial Number...: SGH444039B

### Check swap space
# swapinfo
# swapinfo -m     <- IN MB
# swapinfo -tm    <- Disp Total Row

### Check attached Disk/devices/hws
# ioscan -funC disk
# ioscan -C disk
# ioscan -fnC lan
# ioscan -fnC tape
# ioscan -fnC lun

Here:
-u: Show usable devices i.e don;t rescan
-f: Full listing
-C: Show Class
-n: Device name

### Format a disk
# ioscan -funC disk
Class     I H/W Path     Driver S/W State   H/W Type     Description
=====================================================================
disk      1 0/0/1/1.2.0 sdisk CLAIMED     DEVICE       HP 73.4GST373454LC
                         /dev/dsk/c1t2d0   /dev/rdsk/c1t2d0
..
..

# mediainit /dev/rdsk/c1t2d0

### Disk detailed info
# diskinfo -v /dev/rdsk/c1t2d0

--Shirish Shukla

backup using script imp files linux

2012-03-11T23:05:00.002-07:00

Many time we come across situation to take a backup of file daily/weekly or sometime every hour .

Yes it may be that your filesystem are auto backuped by your backup tools as Snapshot/Veritas netbackup etc.. but still we always come across situation to that we want our some critical file (/etc/passwd, /etc/httpd/conf/httpd.conf etc..) that had changed 1 hour back .

Below a small and simple script that can help us a way .. just schedule this in your crontab .. as per your requirement .

## MyBackup.sh

#!/bin/bash
#Shirish Shukla
#######################################
## Files to be backuped
Sources="/etc/passwd, /etc/group, /etc/shadow"
## Backup Save at Target:
Targetpath=/usr/Backup
#######################################
if [ ! -d $Target-path ]
then
    mkdir -p $Targetpath
fi
#######################################
create=`date +%a-%d-%b-%Y-AT:%H:%M`
delete=`date --date '1 month ago' +%a-%d-%b-%Y`
#######################################
for fles in `echo $Sources`
do
   fle=`echo $fles | sed "s/,//g"`
    if [ ! -e $fle ]
    then
          echo "file: $fle not EXIST"
    fi
    lst=` echo $fle | awk -F"/" '{print $NF}'`
    tar -jcf $Targetpath/$lst-$create.bz2 $fle
done
#######################################
## Now delete 1 month old backups if exists any
rm -fr $Targetpath/*$delete*
#######################################

## Check Backup

# ls -lrt /usr/Backup/
-rw-r--r-- 1 root root 500 Feb 11 11:47 shadow-Sat-11-Feb-2012-AT:11:47.bz2
-rw-r--r-- 1 root root 938 Feb 11 11:47 passwd-Sat-11-Feb-2012-AT:11:47.bz2
-rw-r--r-- 1 root root 500 Feb 11 11:47 group-Sat-11-Feb-2012-AT:11:47.bz2

## Schedule crontab to take it 2 hour

# chmod 755 /root/MyBackup.sh
# crontab -e
01 */2 * * * /root/MyBackup.sh

> Shirish Shukla

Monitor Your System Performance

2011-09-07T07:26:00.000-07:00

Xxxxxxxxxxxxxxx Monitor Your System Performance xxxxxxxxxxxxxxxxxxxxX
[root@server ~]# uptime
13:14:02 up 1:30, 2 users, load average: 0.04, 0.26, 0.27

[root@server ~]# ps -eo %u | sort | uniq -c | sort -rn
56 root
22 nagios
8 apache
1 xfs

[root@server ~]# sar -c ## Process/sec
Linux 2.6.18-164.el5 (server.scratch.com) 08/24/2011
11:50:01 AM proc/s
12:00:01 PM 6.87
12:10:01 PM 6.90
12:20:01 PM 7.10
12:30:01 PM 6.77
12:40:01 PM 6.99
12:50:01 PM 6.85
01:00:01 PM 6.83
01:10:01 PM 6.92
Average: 6.90

[root@server ~]# sar -b ## Data r/wr ps
Linux 2.6.18-164.el5 (server.scratch.com) 08/24/2011
11:50:01 AM tps rtps wtps bread/s bwrtn/s
12:00:01 PM 24.81 0.18 24.63 6.37 376.94
12:10:01 PM 26.14 0.33 25.81 10.68 388.21
12:20:01 PM 57.68 28.05 29.63 620.21 466.02
12:30:01 PM 24.16 0.13 24.03 1.92 369.00
12:40:01 PM 24.55 0.10 24.44 1.70 374.73
12:50:01 PM 25.07 0.14 24.93 4.31 380.10
01:00:01 PM 24.95 0.58 24.37 6.20 377.88
01:10:01 PM 24.57 0.01 24.56 0.04 376.16
Average: 28.98 3.68 25.30 81.17 388.59

[root@server ~]# iostat -k
Linux 2.6.18-164.el5 (server.scratch.com) 08/24/2011

avg-cpu: %user %nice %system %iowait %steal %idle
0.40 0.00 3.84 0.44 0.00 95.32

Device: tps kB_read/s kB_wrtn/s kB_read kB_wrtn
sda 6.60 32.24 65.92 177987 363873
sda1 0.10 0.21 0.00 1163 5
sda2 6.50 32.01 65.92 176684 363868
dm-0 20.19 31.54 65.91 174109 363844
dm-1 0.02 0.08 0.00 440 0
dm-2 0.06 0.25 0.00 1397 20
dm-3 0.03 0.11 0.00 613 4

# cat /proc/stat
cpu 1864 0 16482 416939 2375 34 527 0
cpu0 1864 0 16482 416939 2375 34 527 0
intr 2416023 2368439 12 0 2 2 0 5 0 1 0 0 0 116 0 0 21 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 29989 0 0 0 0 0 0 0 37 0 0 0 0 0 0 0 17399 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 ctxt 258727
btime 1314166387
processes 32539
procs_running 1
procs_blocked 0

# cat /proc/meminfo
MemTotal: 218872 kB
MemFree: 36680 kB
Buffers: 40416 kB
Cached: 79080 kB
SwapCached: 0 kB
Active: 116728 kB
Inactive: 47320 kB
HighTotal: 0 kB
HighFree: 0 kB
LowTotal: 218872 kB
LowFree: 36680 kB
SwapTotal: 614384 kB
SwapFree: 614384 kB
Dirty: 460 kBWriteback: 0 kB
AnonPages: 44556 kB
Mapped: 15936 kB
Slab: 11628 kB
PageTables: 2320 kB
NFS_Unstable: 0 kB
Bounce: 0 kB
CommitLimit: 723820 kB
Committed_AS: 376900 kB
VmallocTotal: 802808 kB
VmallocUsed: 3564 kB
VmallocChunk: 798832 kB
HugePages_Total: 0
HugePages_Free: 0
HugePages_Rsvd: 0
Hugepagesize: 4096 kB

[root@server ~]# cat /proc/cpuinfo
processor : 0
vendor_id : GenuineIntel
cpu family : 6
model : 23
model name : Pentium(R) Dual-Core CPU E5300 @ 2.60GHz
stepping : 10
cpu MHz : 2592.870
cache size : 2048 KB
fdiv_bug : no
hlt_bug : no
f00f_bug : no
coma_bug : no
fpu : yes
fpu_exception : yes
cpuid level : 13
wp : yes
flags : fpu vme de pse tsc msr pae mce cx8 apic mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss constant_tsc up pni
bogomips : 5185.74

[root@server ~]# cat /proc/buddyinfo
Node 0, zone DMA 37 33 31 29 19 12 9 2 0 0 0
Node 0, zone Normal 2217 861 467 317 71 17 6 1 1 0 0
[root@server ~]#

[root@server ~]# cat /proc/execdomains
0-0 Linux [kernel]

[root@server ~]# cat /proc/filesystems
nodev sysfs
nodev rootfs
nodev bdev
nodev proc
nodev cpuset
nodev binfmt_misc
nodev debugfs
nodev securityfs
nodev sockfs
nodev usbfs
nodev pipefs
nodev anon_inodefs
nodev futexfs
nodev tmpfs
nodev inotifyfs
nodev eventpollfs
nodev devpts
ext2
nodev ramfs
nodev hugetlbfs
iso9660
nodev mqueue
ext3

[root@server ~]# cat /proc/loadavg
0.33 0.36 0.29 1/92 2916

[root@server ~]# cat /proc/locks
1: POSIX ADVISORY READ 2689 fd:00:320039 4 4
2: POSIX ADVISORY WRITE 2732 fd:00:931460 0 EOF
3: POSIX ADVISORY READ 2689 fd:00:320021 4 4

[root@server ~]# cat /proc/net/tcp
sl local_address rem_address st tx_queue rx_queue tr tm->when retrnsmt uid timeout inode
0: 00000000:0185 00000000:0000 0A 00000000:00000000 00:00000000 00000000 0 0 7642 1 c8adbb40 3000 0 0 2 -1
1: 0100007F:0CEA 00000000:0000 0A 00000000:00000000 00:00000000 00000000 27 0 7887 1 c8adb240 3000 0 0 2 -1
2: 00000000:008B 00000000:0000 0A 00000000:00000000 00:00000000 00000000 0 0 8138 1 c8ada4c0 3000 0 0 2 -1
3: 00000000:006F 00000000:0000 0A 00000000:00000000 00:00000000 00000000 0 0 7482 1 c9720040 3000 0 0 2 -1
4: 00000000:0015 00000000:0000 0A 00000000:00000000 00:00000000 00000000 0 0 7778 1 c8adb6c0 3000 0 0 2 -1

[root@server ~]# cat /proc/net/udp
sl local_address rem_address st tx_queue rx_queue tr tm->when retrnsmt uid timeout inode
9: 0A08A8C0:0089 00000000:0000 07 00000000:00000000 00:00000000 00000000 0 0 8108 2 c4db8d00
9: 0908A8C0:0089 00000000:0000 07 00000000:00000000 00:00000000 00000000 0 0 8106 2 c4db32c0
9: 0808A8C0:0089 00000000:0000 07 00000000:00000000 00:00000000 00000000 0 0 8104 2 c4db36c0
9: 0708A8C0:0089 00000000:0000 07 00000000:00000000 00:00000000 00000000 0 0 8102 2 c4db3ac0
9: 00000000:0089 00000000:0000 07 00000000:00000000 00:00000000 00000000 0 0 8099 2 c8a04080
[root@server ~]# cat /proc/net/protocols
protocol size sockets memory press maxhdr slab module cl co di ac io in de sh ss gs se re sp bi br ha uh gp em
RAWv6 648 -1 -1 NI 0 yes ipv6 y y y n y y y n y y y y n y y y y n n
UDPv6 620 -1 0 NI 0 yes ipv6 y y y n y n y n y y y y n n y y y y n
TCPv6 1248 19 1 no 224 yes ipv6 y y y y y y y y y y y y n n y y y y y
PACKET 444 -1 -1 NI 0 no kernel n n n n n n n n n n n n n n n n n n n
UNIX 416 -1 -1 NI 0 yes kernel n n n n n n n n n n n n n n n n n n n
RAW 500 -1 -1 NI 0 yes kernel y y y n y y n n y y y y n y y y y n n
UDP 508 -1 0 NI 0 yes kernel y y y n y n y n y y y y y n y y y y n
TCP 1136 19 1 no 224 yes kernel y y y y y y y y y y y y n n y y y y y
NETLINK 404 -1 -1 NI 0 no kernel n n n n n n n n n n n n n n n n n n n

[root@server ~]# cat /proc/partitions
major minor #blocks name
8 0 31457280 sda
8 1 104391 sda1
8 2 20860402 sda2
253 0 7168000 dm-0
253 1 512000 dm-1
253 2 3891200 dm-2
253 3 2048000 dm-3

[root@server ~]# cat /proc/schedstat
version 12
timestamp 2436227
cpu0 4336 4336 7 4343 7528 307075 58464 139144 139144 192048 1771799 248611
domain0 00000001 661081 661081 0 0 0 0 0 661081 360 360 0 0 0 0 0 360 58464 58464 0 0 0 0 0 58464 0 0 0 0 0 0 0 0 0 0 0 0

[root@server ~]# cat /proc/stat
cpu 2085 0 18967 484888 2403 42 607 0
cpu0 2085 0 18967 484888 2403 42 607 0
intr 2808623 2749553 12 0 2 2 0 5 0 1 0 0 0 116 0 0 21 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 33013 0 0 0 0 0 0 0 37 0 0 0 0 0 0 0 25861 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
ctxt 302029
btime 1314166387
processes 37438
procs_running 1
procs_blocked 0

[root@server ~]# cat /proc/swaps
Filename Type Size Used Priority
/dev/mapper/MYVOL-SWAPer partition 511992 0 -1
/extraswap file 102392 0 -2

[root@server ~]# cat /proc/scsi/scsi
Attached devices:
Host: scsi0 Channel: 00 Id: 00 Lun: 00
Vendor: VMware, Model: VMware Virtual S Rev: 1.0
Type: Direct-Access ANSI SCSI revision: 02
[root@server ~]# cat /proc/tty/drivers
/dev/tty /dev/tty 5 0 system:/dev/tty
/dev/console /dev/console 5 1 system:console
/dev/ptmx /dev/ptmx 5 2 system
/dev/vc/0 /dev/vc/0 4 0 system:vtmaster
serial /dev/ttyS 4 64-95 serial
pty_slave /dev/pts 136 0-1048575 pty:slave
pty_master /dev/ptm 128 0-1048575 pty:master
unknown /dev/tty 4 1-63 console

[root@server ~]# cat /proc/uptime
5253.31 4967.57

[root@server ~]# cat /proc/version
Linux version 2.6.18-164.el5 (mockbuild@builder16.centos.org) (gcc version 4.1.2 20080704 (Red Hat 4.1.2-46)) #1 SMP Thu Sep 3 03:33:56 EDT 2009

Other that are usefulls :
[root@server ~]# cat /proc/interrupts
[root@server ~]# cat /proc/iomem
[root@server ~]# cat /proc/vmstat
[root@server ~]# vmstat -m

## Check NC status
[root@server ~]# mii-tool eth0

--Shirish Shukla

IMP Linux Services

2011-05-14T22:57:00.000-07:00

xxxxxxxxxxxxx Important Linux Services in Linux and there meanings xxxxxxxxxxxxx

# chkconfig sshd --list                    [To check daemon default on boot running status ]
# service daemon-name status      [Check daemon present status ]
# service --status-all     [Check all running service ]
# ntsysv                                            [Change services status ]

gpm	needed if you want to use the mouse at the console
kudzu	important for detecting new hardware
syslog	important for syslog services
netfs	needed only if there are NFS shares that should be mounted at boot time
network	important for starting network interfaces (e.g. eth eth1bonding...)
random	used for the system entropy pool
atd	needed if the at(1) service is used instead of cron
apmd	Advanced Power Management (APM) daemon is used for laptops and some desktops
isdn	needed if ISDN is being used
iptables	needed if Netfilter (iptables) Firewall is being used
ip6tables	needed if ip6tables Firewall is being used
pcmcia	not needed on servers - needed for laptops
irqbalance	important for distributing interrupts across all CPUs
sendmai	needed if Sendmail is used - Procmail should be used which is more secure
autofs	needed if automounter is used - production applications should not be dependent on automounter
sshd	important for logins via SSH
portmap	needed if e.g. NFS is being used
nfslock	needed if NFS shares are mounted
nfs	needed if server runs the NFS server
mdmonitor	needed only if software RAID is being used
crond	important for running cron jobs
xinetd	needed if xinetd services are being used see /etc/xinetd.d/ for list of services
cups	needed if CUPS is used for the printing system
rhnsd	needed if server should connect to RHN to check for software updates etc.
sysstat	needed to reset system statistics logs
audit	needed only if Linux Audit Subsystem (LAuS) should run for collecting system call audit records
psacct	needed only if kernel process accounting information is needed
smartd	important for monitoring disk problems if hard disks support SMART technology
netdump	important if kernel oops data and memory dumps should be sent to a Netdump server for server crashes

Rest will add sooooonnnn .....

Diff ext2 ext3 ext4

2011-05-14T22:24:00.000-07:00

xxxxxxxxxxxxxxxxxxxxx Diff ext2 ext3 ext4 xxxxxxxxxxxxxxxxxxxxxxxxx

Extended n file system

ext2 :
- Introduced with kernel 1.0 in 1993
- Flexible can handle upto 4TB
- super block feature increase file system performance
- ext2 reserve 5% of disk space for root
- ext2 is popular on USB and other solid-state devices.
This is because it does not have a journaling function.
so it generally makes fewer reads and writes to the drive,
effectively extending the life of the device .
- NO journalalizm

ext3 :
- Provide all the feature of ext 2 + journaling and backward compatibility .
- can upgrade ext2 to ext3 without loss of data.
- journaling feature speed up the system to recover the state after power-failure
or improper mount unmount etc.
- Example: In ext2 in an improper unmount or in-between power-off etc.. so in time
of receiver it checks whole file system .
But in ext3 it keeps record of uncommitted file transactions and checks applied
on on them so system will come back up in faster and quicker .
-

ext4:
- Introduced with kernel 2.6.28
- Ext4 is a deeper improvement over Ext3
- support larger filesystem, faster checking, nanosecond timestamps,
and verification of the journal through checksums.
- It’s backward and forward compatible with versions 2 and 3, so we can
mount a ext2 or ext3 filesystem as ext4 .
- The main benefits that ext4 has over ext3 are:
- faster time-stamping
- faster file system checking
- journaling check-sums
- extents (basically automatic space allocation to avoid fragmentation)

What is Journalism in linxu file syatem ?
A journaling file system is a file system that keeps track of the changes that will be made in
a journal (usually a circular log in a dedicated area of the file system) before committing them to
the main file system. In the event of a system crash or power failure, such file systems are quicker
to bring back online and less likely to become corrupted.

File Permission Linux

2011-05-14T22:21:00.000-07:00

xxxxxxxxxxxxxxxxxxxxxx File Permission xxxxxxxxxxxxxxxxxx

Set user ID, set group ID, sticky bit

- SUID or setuid:[4] Change user ID on execution. If setuid bit is set, when the file being executed by any user, the process will have the same rights as the owner of the file being executed.

- SGID or setgid:[2] Change group ID on execution. Same as above, but inherits rights of the group of the owner of the file on execution. For directories it also may mean that when a new file is created in the directory it will inherit the group of the directory (and not of the user who created the file).

- Sticky bit:[1] It was used to trigger process to "stick" in memory after it is finished, now this usage is obsolete. Currently its use is system dependent and it is mostly used to suppress deletion of the files that belong to other users in the folder where you have "write" access to.
               -->> If the sticky bit is set for a directory, only the owner of that directory or the owner of a file can delete or rename a file within that directory.

               EG: Login as root
                                     # mkdir /usr/Shirish
                                     # touch /usr/Shirish/shukla
                                     # chmod -R 1777 /usr/Shirish/shukla
                      Login as normal user : sks
                                     # ls -l /usr/Shirish/shukla
                                        -rwxrwxrwt 1 root root 16 Feb 11 00:31 /usr/Shirish/shukla
                                     # rm -fr /usr/Shirish/shukla
                                        rm: cannot remove `/usr/Shirish/shukla': Operation not permitted


SUID bit is set for files ( mainly for binary files only, note It'll not work on perl or shell scripts).
The SUID permission makes a binary to run as the user who is the owner of the binary, rather than the user who started it.

SGID, it will run with the privileges of the files group owner, instead of the privileges of the person running the program.

-----------------------------------------------------------------------------------
0755 -> setuid, setgid, sticky bits are cleared        000
1755 -> sticky bit is set                                            001
2755 -> setgid bit is set                                       010
3755 -> setgid and sticky bits are set                      011
4755 -> setuid bit is set                                           100
5755 -> setuid and sticky bits are set                      101
6755 -> setuid and setgid bits are set                     110
7755 -> setuid, setgid, sticky bits are set              111
-----------------------------------------------------------------------------------

Shirish Shukla
Any comments are welcome .

Types of Processes in linux

2011-05-03T21:05:00.000-07:00

xxxxxxxxxxxxxxxxxx Types of Process in Linux xxxxxxxxxxxxxxxxxxxxxxxx

Every application it may be system specific or application daemon specific. It have to started as process
in background or foreground as designed.

Below are the few common process states:

Runnable: Process started and it's running and is in active queue in meantime it may in waiting for CPU resource.

Stopped: Process started and stopped in between but is not fully killed and can run if started again.

Sleeping/Waiting: Process started and at meantime there are to many request to CPU from some other process or it's is waiting for another process to complete.

Zombie: Process started and started another child process and then parent process gone/died, in such condition that child process doesn't know how to end, so it's hang around but living, such process is known as zombie process.

More About Foreground/Background Process < fg and bg command linux >

how a normal user update shadow file on password change

2011-04-29T04:21:00.000-07:00

xxxxxxxxxxx How a normal user changes his password and updated shadow file xxxxxxxxxxxxx

Note:
permission on /etc/shadow is: 400
permission on /etc/password : 644
permission on /usr/bin/passwd : 4755 ( suid is set)

Can root change own/others password ?: yes (Even he is having read permission on shadow,
but ofcourse root can update any file which is on properly mounted partition)

But can a normal user change his pasword ? : Yes (HOW? he is not having write permission on password and even not having read permission on shadow so how????)

Here's the solution why??

# which passwd
/usr/bin/passwd

# ls -l /usr/bin/passwd
-rwsr-xr-x 1 root root 27768 Jan 6 2007 /usr/bin/passwd

Note: The permission on command binary /usr/bin/passwd is 4755 mean any user can execute it and suid is set on it mean, it must be executed as root it's dose not matter who is executing it, and root have authority to update any file .

But if we look into this scenario then can user keep any password of him and can he change any's password Noooo???

Because passwd binary it's itself authenticate via PAM and run accordingly.

=> inode is is data structure in unix/linux file system

ssh without password

2011-04-21T07:13:00.000-07:00

xxxxxxxxxxxxxxxxxxxxx SSH Login Without Password By- Shirish Shukla xxxxxxxxxxxxxxxxxxxxxxx

Example: ssh from shirish@client-1 to shukla@server-1 without password
Server-1: 192.168.8.10
Client-1: 192.168.8.20

#####ON Client-1: 192.168.8.20 : user shirish
### Login as shirish

# ssh-keygen -t dsa
----------------------------------------------->> Just press Enter don't type anything

Generating public/private dsa key pair.
Enter file in which to save the key (/home/shirish/.ssh/id_dsa): <--Enter
Created directory '/home/shirish/.ssh'.
Enter passphrase (empty for no passphrase):                          <--Enter
Enter same passphrase again:                                               <--Enter
Your identification has been saved in /home/shirish/.ssh/id_dsa.
Your public key has been saved in /home/shirish/.ssh/id_dsa.pub.
The key fingerprint is:
d8:6c:cb:2a:e7:24:01:43:9f:96:4a:45:e6:93:9b:f4 shirish@my.scratch.com

# ssh-copy-id -i .ssh/id_dsa.pub shukla@192.168.8.10

The authenticity of host '192.168.8.10 (192.168.8.10)' can't be established.
RSA key fingerprint is e8:0b:8a:d3:1a:d1:ce:ec:d8:f9:13:31:79:c8:03:ed.
Are you sure you want to continue connecting (yes/no)? yes                        <--type yes
Warning: Permanently added '192.168.8.10' (RSA) to the list of known hosts.

Password:                                <-- type password of shukla on Server-1: 192.168.8.10

Now try logging into the machine, with "ssh 'shukla@192.168.8.10'", and check in:

.ssh/authorized_keys

to make sure we haven't added extra keys that you weren't expecting.

#####ON Server-1: 192.168.8.10
### Login as shukla and confirm following
1> permission of /home/shukla/.ssh    700
$ ls -lrthd .ssh/
drwx------ 2 shukla shukla 4.0K Mar 12 13:51 .ssh/

2> permission of /home/shukla/.ssh/authorized_keys    600
$ ls -lrth .ssh/
-rw------- 1 shukla shukla 614 Mar 12 13:51 authorized_keys

########### Now login as shirish on Client-1:192.168.8.20
## ssh shukla@192.168.8.10
------------------------------------------------------>> It will not prompt for password

# Faced any problem Feedback in above contact me
#===============================Scratch=============================#
# AND Many More .....................Linux is Endless                       #
#=========================== Hope you Liked IT ========================#
#                                           SSH-I -- BY Shirish Shukla   #
#                                                   RHC Engineer 2010 #
#                                              shirish.linux@gmail.com #
#                                               shirishlinux.blogspot.com #
#    "Give Respect To Time One Day At Right Time, Time Will Respect You" #
#=================================================================#
# TRy Hard theres nothing that are un-achievable by HARDdd-WORKkk      #
#=================================================================#

Script to take MBR backup

2011-03-23T09:41:00.005-07:00

xxxxxxxxxxxx BASH To Take MBR BAckup -- Shirish Shukla xxxxxxxxxxxxx

#!/bin/bash

hdds=$(echo /dev/[hs]d?)

for hdd in $hdds

## take only last name of dir

base=$(basename $hdd)

##take MBR Backup 0-512 bytes

dd if=$hdd of=/tmp/$base.mbr count=1 bs=512

echo $hdd

done

Install Configure Nagios

2011-03-16T07:58:00.000-07:00

xxxxxxxxxx Install & Manage NAGIOS Monitoring tool by Shirish Shukla xxxxxxxxxxxxx

Nagios® is a system and network monitoring application. (Description from some source)
Some of the many features of Nagios® include:
- Monitoring of network services (SMTP, POP3, HTTP, NNTP, PING, etc.)
- Monitoring of host resources (processor load, disk usage, etc.)
- Simple plugin design that allows users to easily develop their own service checks
- Parallelized service checks
- Ability to define network host hierarchy using "parent" hosts, allowing detection of and     distinction between hosts that are down and those that are unreachable
- Contact notifications when service or host problems occur and get resolved (via email, pager,   or user-defined method)
- Ability to define event handlers to be run during service or host events for proactive          problem resolution
- Automatic log file rotation
- Support for implementing redundant monitoring hosts
- Optional web interface for viewing current network status, notification and problem history,   log file, etc.

PREREQUISITE:
=============
Apache (https)
gcc libraries

Nagios Tols:
============
# mkdir /root/SW
wget http://prdownloads.sourceforge.net/sourceforge/nagios/nagios-3.2.3.tar.gz
wget http://prdownloads.sourceforge.net/sourceforge/nagiosplug/nagios-plugins-1.4.11.tar.gz

##Adduser and groups

# useradd -m nagios
# passwd nagios

# groupadd nagios              <--Just for confirmation
# usermod -G nagios nagios     <--Just for confirmation

# groupadd nagcmd
# usermod -a -G nagcmd nagios
# usermod -a -G nagcmd wwwrun <--Not Require(optional) need to create group wwwrun before

INSTALLATION:
=============
# cd /root/SW
# tar xzf nagios-3.2.3.tar.gz
# cd nagios-3.2.3

# ./configure --with-command-group=nagcmd
# make all
# make install
# make install-init
# make install-config
# make install-commandmode

# vi /usr/local/nagios/etc/objects/contacts.cfg
At line
35: Change --> email           youadmin-mail-id

# make install-webconf
# htpasswd -c /usr/local/nagios/etc/htpasswd.users nagiosadmin
Note: if you want to change admin "nagiosadmin" name chanhe all in "/usr/local/nagios/etc/cgi.cfg" file too .

##Start httpd(Apache)
# /etc/init.d/httpd restart
# chkconfig httpd on

### Instal nagios-plugin
# tar xzf nagios-plugins-1.4.11.tar.gz
# cd nagios-plugins-1.4.11
# ./configure --with-nagios-user=nagios --with-nagios-group=nagios
# make
# make install

#### Start nagios
# /etc/init.d/nagios restart
# chkconfig nagios on

###### How to OPERATE

# Webadmin panel
http://your-ip/nagios/ < Provide above seted id & password---

EG: To Check All Hosts without options You can set it to your default apache hosting file for your monitoring purpose
http://192.168.8.10/nagios/cgi-bin/status.cgi?host=all

### Want default as above to your ip
# vi /var/www/html/index.html
<html>
<head>
<META HTTP-EQUIV="Refresh"
CONTENT="2; URL=http://192.168.8.10/nagios/cgi-bin/status.cgi?host=all">
</head>
<body bgcolor="pink">
<br />
<br />
<br />
<br />
<br />
<br />
<Center>
<h1> <font color="green"> Wait 2 Sec.............</font></h1>
</body>
</html>

##Save and relaod httpd

Now just type your ip on browser and <---Enter

####################################################
#################Add your servers to monitor ############
###################################################
# cd /usr/local/nagios    <-- Nagios default files

# cd /usr/local/nagios/etc/objects <<-- All cfg file server's config file to monitor

# cat /usr/local/nagios/etc/nagios.cfg <<<-- NAgios main config file

# vi /usr/local/nagios/etc/nagios.cfg <<<--Add your own config dirs where your all server cfg file will reside

==>Add below line

cfg_dir=/usr/local/nagios/etc/lnx-servers

# cd usr/local/nagios/etc/lnx-servers

# vi my-samba_server

##############################################################
############# HOST DEFINITION ###############################
##############################################################
# HOST DEFINITION
   define host{
        use                     linux-server            ; defined in template
        host_name               scratch-samba.8.10
        alias                   samba-server
        address                 192.168.8.10
        }

# HOST GROUP DEFINITION (Optional, you can add multiple members to your already created group seperated by comma)
define hostgroup{
        hostgroup_name my-servers             ; The name of the hostgroup
        alias           MY Linux Servers         ; Long name of the group
        members         scratch-samba.8.10      ; Comma separated list of hosts that belong to this group
       }

##############################################################
####################### SERVICE DEFINITIONS #################
##############################################################

###Ping check
define service{
        use                             local-service                 ; defined in template /usr/local/nagios/etc/objects/templates.cfg
        host_name                       scratch-samba.8.10
        service_description             PING
        check_command                   check_ping!100.0,20%!500.0,60% ; Defined in commnd file /usr/local/nagios/etc/objects/commands.cfg
        }

### SSH service Check
define service{
        use                             local-service
        host_name                       scratch-samba.8.10
        service_description             SSH
        check_command                   check_ssh!-t 5 -r "OpenSSH_4.2"
        }

define service{
        use                             local-service         ; Name of service template to use
        host_name                       scratch-samba.8.10
        service_description             samba
        check_command                   check_http
        }

define service{

        use                     local-service           ; Inherit default values from a template
        host_name               scratch-samba.8.10
        service_description     SMTP
        check_command           check_smtp
        }

#check port 139
define service{
        use                     local-service           ; Inherit default values from a template
        host_name               scratch-samba.8.10
        service_description     Samba_port139
        check_command           check_tcp!139
        }

##########################################################################

## Nagios Fine tunning file (Do not replace original line comment that then add below line)
# vi /usr/local/nagios/etc/cgi.cfg

### Don't show pending satate of service
use_pending_states=0

### Disable webadmin auth
use_authentication=0

### Want to authorize an user shukla to have all admin rights for weadmin panel
authorized_for_system_information=shukla
authorized_for_configuration_information=shukla
authorized_for_system_commands=shukla
authorized_for_all_hosts=shukla
authorized_for_all_services=shukla
authorized_for_all_service_commands=shukla
authorized_for_all_host_commands=shukla

### Want default guest user, WARN: dont' allow this
default_user_name=guest

### Want an read only user
#htpasswd -c /usr/local/nagios/etc/htpasswd.users user1
#using command add more users
authorized_for_read_only=user1

### Want to change ping syntax
ping_syntax=/bin/ping -n -U -c 5 $HOSTADDRESS$

### Refresh rate of cgi (status, statusmap, extinfo, and outages) in sec
refresh_rate=60

### Want to play sound on webpanel if error occour on network
## Plcace your audio file at
# /usr/local/nagios/share/media
##Un commen tbelow lines after adding resp audio files
#host_unreachable_sound=hostdown.wav
#host_down_sound=hostdown.wav
#service_critical_sound=critical.wav
#service_warning_sound=warning.wav
#service_unknown_sound=warning.wav
#normal_sound=noproblem.wav

### dont allow to change author name while submitting comment
lock_author_names=0

# vi /usr/local/nagios/etc/nagios.cfg

### Change log path
log_file=/usr/local/nagios/var/nagios.log

## Add your specific cfg file of server to monitor
cfg_file=/usr/local/nagios/etc/objects/myserver.cfg

## Add you dir contain your server cdf file to monitor all
cfg_dir=/usr/local/nagios/etc/my-lnx-servers

## Host update interval in sec
status_update_interval=5

## Change nagios user & Group (NOT Recomended)
nagios_user=nagios
nagios_group=nagios

## Add you own command file
check_external_commands=0
command_check_interval=-1
command_file=/usr/local/nagios/var/rw/nagios.cmd <<--As you want
external_command_buffer_slots=4096

## Nagios store his pid at
lock_file=/usr/local/nagios/var/nagios.lock

##### agios Log rotation
#       n       = None - don't rotate the log
#       h       = Hourly rotation (top of the hour)
#       d       = Daily rotation (midnight every day)
#       w       = Weekly rotation (midnight on Saturday evening)
#       m       = Monthly rotation (midnight last day of month)

log_rotation_method=d
log_archive_path=/usr/local/nagios/var/archives

##Use syslog to do so
use_syslog=1

##### MAXIMUM SERVICE CHECK SPREAD in munute
max_service_check_spread=30

### HOST FRESHNESS CHECK OPTION (Nagios chek periodically freshmess of hosts)
check_host_freshness=1
host_freshness_check_interval=20

### Change date format
#       us              (MM-DD-YYYY HH:MM:SS)
#       euro            (DD-MM-YYYY HH:MM:SS)
#       iso8601         (YYYY-MM-DD HH:MM:SS)
#       strict-iso8601 (YYYY-MM-DDTHH:MM:SS)
date_format=us

##Enable perl support
##not in use if u have not compliled nagios with perl
p1_file=/usr/local/nagios/bin/p1.pl
###disable =0
enable_embedded_perl=1

# ADMINISTRATOR EMAIL/PAGER ADDRESSES
admin_email=nagios@localhost

# DEBUG LEVEL
#          -1 = Everything
#          0 = Nothing
#          1 = Functions
#          2 = Configuration
#          4 = Process information
#          8 = Scheduled events
#          16 = Host/service checks
#          32 = Notifications
#          64 = Event broker
#          128 = External commands
#          256 = Commands
#          512 = Scheduled downtime
#          1024 = Comments

debug_level=0

# DEBUG VERBOSITY
# Values: 0 = Brief output
#         1 = More detailed
#         2 = Very detailed

debug_verbosity=1

# DEBUG FILE
debug_file=/usr/local/nagios/var/nagios.debug

############################ BASIC Checking #############################

### Check Your Config files for error

# /usr/local/nagios/bin/nagios -v /usr/local/nagios/etc/nagios.cfg
# /etc/init.d/nagios start

########## Tunnning

1> Want any new updates to be check every minute (Default 5 minute)
# vi /usr/local/nagios/etc/objects/templates.cfg

check_interval      1 ; Actively check the host every 1 minutes

2> I want to check default ping of my server
check_command                   check-ping

3> I want to use all config waht i defined in my template linux-server to windows-server
Add below line in windows.cfg
use linux-server

xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

# Faced any problem Feedback in above contact me
#===============================Scratch===============================#
# AND Many More .....................Linux is Endless                 #
#========================== Hope you Liked IT ========================#
#                                         NAGIOS -- BY Shirish Shukla #
#                                                   RHC Engineer 2010 #
#                                             shirish.linux@gmail.com #
#                                           shirishlinux.blogspot.com #
# "Give Respect To Time One Day At Right Time, Time Will Respect You" #
#=====================================================================#
# TRy Hard theres nothing that are un-achievable by HARDdd-WORKkk     #
#=====================================================================#

mysql master -slave Replication

2011-03-16T07:38:00.000-07:00

..........mysql master slave replication configuration on LINUX.......- Shirish Shukla

Some Basics:
Port No: 3306 (TCP/UDP)

IPADDRESS_Set as per your requirement

SYATEM 1 >> master   : 192.168.8.10
SYATEM 2 >> Slave    : 192.168.8.20

1> Installation on both server

# yum install mysql*

# /etc/init.d/mysqld restart
# /etc/init.d/mysqld restart

                                                      ### Set root password
# mysqladmin -u root password x                       ### replace x is ur password

Login in mysql:

# mysql -u root -px                                   ### replace x is as ur password aviod direct
                                                      ### passing of password for security reason
# mysql -u root -p     <Enter>
Enter password:    <Enter Password>
mysql> exit

2> ON MASTER--192.168.8.10

# cp /etc/my.cfg /etc/my.cfg_Org                      ### Keep a copy
# vi /etc/my.cnf

[mysqld]
datadir=/var/lib/mysql
socket=/var/lib/mysql/mysql.sock
user=mysql
###Default to using old password format for compatibility with mysql 3.x
### clients (those using the mysqlclient10 compatibility package).
old_passwords=1

server-id=1
binlog-do-db=SHUKLA               ### databases which you want to replicate
binlog-do-db=SHIRISH                # create these databases before SEE
                                    # at END BASIC MYSQL COMMANDS
                                    # use, to add in 1 line or add seperately
binlog-ignore-db=mysql            ### Input the database that should be ignored
binlog-ignore-db=test               # for replication

log-bin=/var/lib/mysql/mysqld-bin

[mysqld_safe]
log-error=/var/log/mysqld.log
pid-file=/var/run/mysqld/mysqld.pid
relay-log=/var/log/mysql-relay-bin

# mysql -u root -p

mysql> grant replication slave on *.* to replication@192.168.8.20 identified by 'slave';
mysql> GRANT ALL PRIVILEGES ON *.* TO replication;

Cross check user replication
======================
mysql> use mysql;
mysql> select * from user where User='replication';        ### must show 'Y' in most fields specially in "Super_priv"

#### Now Craete some database and tables

mysql> CREATE DATABASE SHIRISH;
mysql> use SHIRISH;
mysql> create table members(name char(20), age varchar(20));
mysql> show tables;
mysql> insert into members(name, age) values ('Shirish Shukla', 23);
mysql> insert into members(name, age) values ('Shirish Shukla-2', 23);
mysql> insert into members(name, age) values ('Shirish Shukla-3', 23);
mysql> select * from members;
+------------------+------+
| name             | age |
+------------------+------+
| Shirish Shukla | 23   |
| Shirish Shukla-2 | 23   |
| Shirish Shukla-3 | 23   |
+------------------+------+
3 rows in set (0.00 sec)

mysql> exit

3> ON SLAVE--192.168.8.20
# cp /etc/my.cfg /etc/my.cfg_Org               ### Keep a copy
# vi /etc/my.cnf
[mysqld]
datadir=/var/lib/mysql
socket=/var/lib/mysql/mysql.sock
user=mysql
# Default to using old password format for compatibility with mysql 3.x
# clients (those using the mysqlclient10 compatibility package).
old_passwords=1

server-id=2
master-host = 192.168.8.10
master-user = replication
master-password = slave
master-port = 3306
log-bin=/var/lib/mysql/mysqld-bin

[mysqld_safe]
log-error=/var/log/mysqld.log
pid-file=/var/run/mysqld/mysqld.pid
relay-log=/var/log/mysql-relay-bin

# mysql -u root -p

mysql> stop slave;
mysql> CHANGE MASTER TO MASTER_HOST='192.168.8.10',MASTER_USER='replication',MASTER_PASSWORD='slave';
mysql> GRANT ALL PRIVILEGES on *.* TO replication

Cross check user replication
======================
mysql> use mysql;
mysql> select * from user where User='replication';        ### must show 'Y' in most fields specially in "Super_priv"

mysql> start slave;
mysql> show slave status\G;
*************************** 1. row ***************************
             Slave_IO_State: Waiting for master to send event            <1>
                Master_Host: 192.168.8.10                                 <2>
                Master_User: replication                                  <3>
                Master_Port: 3306                                         <4>
              Connect_Retry: 60
            Master_Log_File: mysqld-bin.000008                            <5>
        Read_Master_Log_Pos: 223                                          <6>
             Relay_Log_File: mysqld-relay-bin.000002
              Relay_Log_Pos: 361
      Relay_Master_Log_File: mysqld-bin.000008
           Slave_IO_Running: Yes                                          <7>
          Slave_SQL_Running: Yes                                          <8>
            Replicate_Do_DB:
        Replicate_Ignore_DB:
         Replicate_Do_Table:
     Replicate_Ignore_Table:
    Replicate_Wild_Do_Table:
Replicate_Wild_Ignore_Table:
                 Last_Errno: 0
                 Last_Error:
               Skip_Counter: 0
        Exec_Master_Log_Pos: 223                                          <9>
            Relay_Log_Space: 361
            Until_Condition: None
             Until_Log_File:
              Until_Log_Pos: 0
         Master_SSL_Allowed: No
         Master_SSL_CA_File:
         Master_SSL_CA_Path:
            Master_SSL_Cert:
          Master_SSL_Cipher:
             Master_SSL_Key:
      Seconds_Behind_Master: 0                                           <10>
1 row in set (0.01 sec)

ERROR:
No query specified

#### CROSS check some things in above;
<1>Always "Waiting for master to send event" if unable to connect then report or restrat
<2>Muyst show master IP
<3>Show user as set above
<4>PORT 3306
<5>must match with below (show master status;) FILE
<6>must match with below (show master status;) Position
        On master RUN
        mysql> show master status;
+-------------------+-----------+-------------------------------+------------------------+
| File              | Position | Binlog_Do_DB                  | Binlog_Ignore_DB      |
+-------------------+-----------+-------------------------------+------------------------+
| mysqld-bin.000008 |      223 | SHUKLA,SHIRISH,SHUKLA,SHIRISH | mysql,test,mysql,test |
+-------------------+-----------+-------------------------------+------------------------+

<7>Must show Yes
<8>Must show Yes
<9> SAME As <6>
<10>Must show limited sec diff < 2 or 0 sec but not 'NULL'

3> TESTING MASTER SLAVE
#### Now cross check is replacition done properly or not !!!

mysql> show databases;
mysql> use SHIRISH;
mysql> show tables;       <--- Compare with master
mysql> select * from members; <--- Compare with master

### Now create a new table as LINUX at MASTER;

mysql> SHOW TABLES;
mysql> create table linux(name char(20), age varchar(20));
mysql> insert into linux(name, age) values ('Shirish Shukla', 23);
mysql> SHOW TABLES;
+--------------------------+
| Tables_in_SHIRISH       |
+--------------------------+
| linux                   |
| members                 |
+--------------------------+
2 rows in set (0.00 sec)

## now at slave

mysql> use SHIRISH;
mysql> show tables;
mysql> select * from linux;    << MUST SHOW SAME AS MASTER JUST UPDATED>>

Some Tuning.....add below in /etc/my.conf of both master and slave........

==========================================================================
||                    MASTER SLAVE <--> MASTER SLAVE                    ||
==========================================================================

Continue above configuration and add BELOW....

                     192.168.8.10      192.168.8.20
                       SYSTEM-1          SYSTEM-2
Now Above AS:          Master <------> SLAVE
                       SLAVE   <------> MASTER2

ON SYSTEM-1
# vi /etc/my.cnf    <<--Add below lines

master-host = 192.168.8.20
master-user = replication
master-password = slave
master-port = 3306

# /etc/init.d/mysqld restart

# mysql -u root -px
mysql> stop slave;
mysql> grant replication slave on *.* TO ayam@'192.168.8.10' identified by 'x';
mysql> grant replication slave on *.* TO ayam@'192.168.8.20' identified by 'x';
mysql> GRANT ALL PRIVILEGES ON *.* TO replication@192.168.8.10;
mysql> GRANT ALL PRIVILEGES ON *.* TO replication@192.168.8.20;
mysql> GRANT ALL PRIVILEGES ON *.* TO replication;
mysql> CHANGE MASTER TO MASTER_HOST='192.168.8.20',MASTER_USER='replication',MASTER_PASSWORD='slave';
mysql> start slave;

ON SYSTEM-2
# vi /etc/my.cnf    <<--confirm below line we had already added in Part -1

## Add below lines
binlog-do-db=SHUKLA               #Databases that you want to replicate
binlog-do-db=SHIRISH
binlog-ignore-db=mysql            # input the database that should be ignored for replication
binlog-ignore-db=test

## Cross varify below to exist we had already added
master-host = 192.168.8.10
master-user = replication
master-password = slave
master-port = 3306

# mysql -u root -px
mysql> stop slave;
mysql> grant replication slave on *.* TO ayam@'192.168.8.10' identified by 'x';
mysql> grant replication slave on *.* TO ayam@'192.168.8.20' identified by 'x';
mysql> GRANT ALL PRIVILEGES ON *.* TO replication@192.168.8.10;
mysql> GRANT ALL PRIVILEGES ON *.* TO replication@192.168.8.20;
mysql> GRANT ALL PRIVILEGES ON *.* TO replication;
mysql> CHANGE MASTER TO MASTER_HOST='192.168.8.10',MASTER_USER='replication',MASTER_PASSWORD='slave';
mysql> start slave;

ON SYSTEM-1
mysql> show slave status\G; < and cross varifie with as we done in PART-1

ON SYSTEM-2
mysql> show slave status\G; < and cross varifie with as we done in PART-1

CROSS Checking:

###################################### BASIC MYSQL COMMANDS ###############################
##Create database SHIRISH
mysql> create database SHIRISH;
##Create Tables into database SHIRISH
mysql> use SHIRISH;
mysql> create table LINUX_USERS(name char(20), age varchar(20));
##Display created table;
mysql> show tables;
##Insert data into table LINUX_USERS
mysql> insert into LINUX_USERS(name,age) values ('Shirish Shukla', 23)
##display created entry into table LINUX_USERS
mysql> select * from shukla;

# Faced any problem Feedback in above contact me
#===============================Scratch===============================#
# AND Many More .....................Linux is Endless                 #
#========================== Hope you Liked IT ========================#
#                                          MYSQL -- BY Shirish Shukla #
#                                                   RHC Engineer 2010 #
#                                             shirish.linux@gmail.com #
#                                           shirishlinux.blogspot.com #
# "Give Respect To Time One Day At Right Time, Time Will Respect You" #
#=====================================================================#
# TRy Hard theres nothing that are un-achievable by HARDdd-WORKkk     #
#=====================================================================#

boot process Linux sort

2011-01-27T08:50:00.000-08:00

Boot Process in sort by Shirring Shukla

In sort boot process of linux OS ....

power on --> BIOS load into RAM --> BIOS moto is to load OS --> for that he perform POST inventry and calls CMOS to know boot order

---> after getting boot order BIOS load it whatever it finds in first sector of hdd into RAM this is what we called MBR

M ----------------------------- B ----------------------------------- R
<----------------------------- 512 bytes --------------------------->
+--------------BS------------+ +--------PT--------+ +----MN----+
                    446                  64                      2
M ------------------------------ B ----------------------------------- R

--> Exaine PT of MBR to know where is active partition (AP) -> Then BIOS load whatever it finds on BS of AP
--> BIOS then load 1SBL(1st satge boot loader) which were put there by anocanda during install time.
--> 1SBL gives CHS # of the /boot/boot.map to BIOS to load 2SBL(2st satge boot loader)
--> 2SBL examine the binary format of grub.conf and follows all instructions given there.
--> with the help of BIOS 2SBL loads Linux kernel vmlinuz-2.4.20-8 into the RAM
--> 2SBL uncompress kernal vmlinuz and filled it into ram waht we see in /proc dirr...
--> Now Linux Kernel is into RAM which is much powerfull than 2SBL and takes total control from it.
--> With the help of BIOS Kernal uncompresses the /boot/initrd-2.4.20-8.img to find filesystem driver.
-> Now HDd driver available and Kernel is into RAM
-> Now Kernel Load /sbin/init program into RAM.
-> /sbin/init* examines /etc/inittab and
                        1> run level (0-6 what ever is is defined) and run an script name
                        2> /etc/rc.d/rc.sysinit in a subshell of inittab shell
                        which calls /etc/sysconfig/network to load networking
                        and start various functions defined in /etc/init.d/functions
                        and Mounts all local filesystems from /etc/fstab and updates /etc/mtab
                        and now function of ec.sysinit ends
                        Short summary of what rc.sysinit does
                             ===================================== in sort waht done by rc.sysinit
                            hostname
                             system logs
                             date and time
                            keyboard
                             system font
                             swap partitions
                             usb
                             file system checks
                             mount the filesystems read/write
                        =====================================

                        3> /etc/rc.d/rc      { as a subshell }
                           /etc/rc.d/rc3.d/K*
                           /etc/rc.d/rc3.d/S* -->   start & stop of services
                           /etc/rc.d/rc.local -->

--> shell inittab is active and by defaults there are 6 mingettys out of which all entered into sleep state
--- except 1
---> this mingetty then executes the /bin/login process and is then it put into sleep state by init
---> and we get promped for username & password
--> * /bin/login execs /usr/bin/passwd which challenges for passwd from
    us which then does authentication and authorization using PAM
---> after Right username and password
---> mingetty then goes into zombie state and is killed by init
---> defined shell loads and we get our shell based command prompt:#$

# Faced any problem Feedback in above contact me
#============================Scratch=================================#
#                                                    AND Many More .....................Linux is Endless               #
#========================== Hope you Liked IT ==========================#
#                                                                                    BOOT PROCESS-- BY Shirish Shukla #
#                                                                                                                RHC Engineer 2010 #
#                                                                                                          shirish.linux@gmail.com #
#                                                                                                        shirishlinux.blogspot.com #
#                        "Give Respect To Time One Day At Right Time, Time Will Respect You" #
#===================================================================#
#                       TRy Hard theres nothing that are un-achievable by HARDdd-WORKkk   #
#===================================================================#

LINUX INTERVIEW QUESTIONS

2011-01-27T08:38:00.001-08:00

Hello Friends,

We all might have faced various interview questions and well aware of as a beginner how tough to clear it at first attempt almost all have too many questions.

Below are some interview question that have faced during my journey in Linux/Unix journey !!

"TELL ME SOMETHING ABOUT YOUR SELF"

0. As usual !!! "Tell me something about yourself"? An annoying question? but everyone have to face this and have to be well prepared as first impression might be your last impression .

Don't loose your confidence or get afraid as you have to sell your knowledge in this competitive market and if you failed here doesn't mean path has end ..

Let's find out how to answer this in well organized order in < 2-3 minutes .

1. Your NAME in full
2. Your qualification in short start with 1-10th -> 11-12th -> Degree

3. Fresher -> Your college project brief explained
Lateral -> Your first job how you got and roles & responsibility

- Small intro about your previous all experience
- Current Job detailed info like day2day activities, roles

- Future opportunity at your current job
- Your future goal (Only if have left some time)

4. That's it from my end IF anything else you want to know then please ask !!

Note: - Don't explain much about your family background unless being asked :)
- Don't be more overconfidence

- Don't show your ego mean judge interviewer and try your best that Interviewer will not feel like he is more technically stronger than me :)
- Don't be short tempered
- Include technical skill-sets for which you have confidence

- Don't be too over smart, as that might create negative impression towards like "WILL SEE HIM IN TECHNICAL ROUND!!! '(';')' '(';')' ...

- Keep cool & calm, as this is not your last opportunity many more has to come at your path .

Okay lest start with some Linux interview technical questions :

Basic Level 1 for freshers or < 2 yr exp..

Expert Level for lateral

What is Linux
Diff Linux & Unix
Diff RHEL 5/6
What's new in RHEL 7
Linux boot process in brief
Port numbers on FTP
Port number of telnet, smtp, dns, dhcp, ntp, http, https
How to check/edit other users cron entries
What is user shell
How to check available shells
How to change your current shell

DNS:

What is DNS
How DNS works
Types of DNS
Types of records in DNS
How to check DNS lookup
How to update DNS zone without service restart
How to check any error in zone file
What & Why NS record in DNS
Master and slave how it's working
How to ensure updates send to slaves
Static vs Dynamic DNS zones
How to update dynamic zones & usages
Fields in zone file
reload for specifiz domain zone

CRONTAB:

What is crontab
Fields in crontab
Where is user specific cron file
What is system specific cron, where are they defined
Use of /etc/crontab file
Eg. Schedule a script run every day at 11:00pm
Schedule a script run every 2 minutes

Backup:

Any backup tools you know?
What is diff tar and zip
gzip pack and unpack
cat gzip file
bazip2 pack and unpack
cat bazip2 file
extract without effecting current file
extract to specific dir

Yum & rpm:

yum:

yum package name
Find current available repos
Install from specific repo
Install local rpm
Find all available version of package
Find when package was installed
Install a specific version of package
Check package integrity
Clear yum cache, required in which case example .
Find package all files
How to setup YUM server
How to setup yum client
How to setup yum proxy

rpm:

rpm package name
install/update/remove etc
Find when package last updated
Find package info, files, dependencies
What is rpmdb
how to re-build

Mail Server:

Do you have experience on any mail server ?

Postfix:

How Postfix or any mail server works
What is configuration file
PORT Number
Check service running or not and listening on which IP
How to send a test mail
Log file path
Check mailq
Flush mailq
Resend, force retry all mails in queue
How to handle maillog rotation
Listen on localhost why ?
Listen is specific IP why ?
Diff master and client setup basic
What is master.cf
Filter any specific user mail -> DISCARD
Mail to specific user -> DISCARD
Allow mail sent to specific domain only
Allow only specific set of users to send mail
Allow mail form a specific subnet
Minimum requirement to setup postfix mail server
Sent mail lost troubleshooting steps .

Specification:

Find Physical or Virtual
Find System vendor name i,e Manufacturer name
Find total RAM
Find total swap
Find total socket, Core, CPU's on server
Find System serial number
Find HBA cards

Troubleshooting:

Total current Load on server, how to check
What is load average, how and where to find and statics interval
Total cpu utilization on server how to calculate
Total memory utilization
Total swap utilization
Add additional swap? how ?
Which process consuming more CPU
Which process consuming more RAM
Which process consuming more SWAP
Which process consuming more no of process
How to find total number of process thread initiated by a process
What is i/o on system, how to find
Which process causing high i/o
Diff paging and caching
What is cpu steal time
What is memory over-commit
Find troubleshoot memory leak
How to enter in single user mode
diff single user and emergency mode
How to recover boot grub password
How to clear cache, why its required and what would be impact of this

Boot level :

How to set grub password
How to set default kernel to boot
How to change kernel parameters during boot
How to repair FS
What is GRUB
Size of MBR, fields in MBR, PT size in MBR
What is rescue mode
How to enter in rescue mode and why required example
Take MBR backup and repair

Networking:

How to assign IP address
How to assign virtual IP address
How to assign temporary IP address
How to change hostname permanent
How to assign temporary hostname
What is Gateway
How to assign Gateway
What is domainname
TCP vs UDP with example of each
OSI layer
How many virtual IP you can assign to a single interface .
What is route table
How to update route table temporary
How to update route table permanent
What is bonding
How to setup network bonding for 2 interface
Mode of bonding
Steps of bonding
Check current status of bond interface
Check members of bond
Bonding vs Bridging in Linux
What is ARP
What is network boot
What is iptables
Tables in iptables
Write iptable to block use of sshd service via port 22 from outside of range 192.168.8.10-192.168.8.50
What is tcpdump
tcpdump take dump of all packets coming from host1 and host 2 on port 3030 on ethernet eth2 and write to file /tmp/a.pcap
Read tcpdump file
What is ip_forwarding

Setup:

How to install Linux RHEL/CentOS OS
Types of installation
What is PXE boot
What is network boot
Rapid Kickstart installation
Any other installation method you know

Volume Management ( LVM ) :

What is LVM
What is File system
Advantage of ext4 over ext3
Advantage of xfs over ext4
What are the fields in /etc/fstab
Ex: create a LV of 5GB and mount of /test
Disk1: /dev/sda
Disk1: /dev/sdb
VG to create: VG01 with above 2 disk
LV: mytestlv
Mount with both dump & pass enabled ? What are these fields ?
How to extend LV
how to reduce LV
How to extend VG
how to reduce VG
How to take snap of LV
How to destroy LV, VG, PV
Find number of PV's in VG
Find free available size in VG
Create LV with all availabel free size in VG
Change VG parameters .

Scripting:

Do you have experience on any scripting language
Bash shell scripting ?
What is first line of script eg. "#! /bin/bash" and why it's there
How to pass arguments in script
How to read arguments in script
How to define array
How to define float value
How to define string
How to print no of arguments passed in script
What is echo $#
What is echo $@
Print 1 to 10 in reverse order
Synatx of for loop
Syntax of while loop
Syntax of if else
Syntax of neted if else
Syntax of case statement
What is getopts
What AWK stands
AWK to print 3rd column
Using grep find how many times word "HELLO" appear in file1
Using egrep find if file1 contains HELLO1 and HELLO2
Diff grep and egrep
Use sed to replace "hello" to "sello" in file

Others:

USe of ip_farwording
Where is config file of sshd service.
What is tunnel
What is mutt
Fields in top command meanings
1>load average 2> %id 3> Mem: 4> SWAP
What is the use of swap partition
Can we increase swap partition size how
Syntax of for loop in bash
Can we change vsftpd default directory location
Can we change Default Directory in apache
Can we use index.php insted of index.html as default page in apache how .
visudo command will open file?
Diff RHEL & Centos
Diff LILO GRUB
Advantages of GRUB
What is iptables, Firewall, netfilter ..?
What is cluster & virtualizaton just basic, what you understand by term..
Whats does 2nd column refer in # ls -l output

.... N.. MANY MORE COMING SOON .... KEEP LEARNING...!!!!

# Faced any problem Feedback in above contact me

#============================Scratch==============a===================#

# AND Many More .....................Linux is Endless #

#========================== Hope you Liked IT ==========================#

# INTVR QSTNS-- BY Shirish Shukla #

# RHC Engineer 2010 #

# shirish.linux@gmail.com #

# shirishlinux.blogspot.com #

# "Give Respect To Time One Day At Right Time, Time Will Respect You" #

#===================================================================#

# TRy Hard theres nothing that are un-achievable by HARDdd-WORKkk #

#===================================================================#

LOGWATCH LINUX

2011-01-27T08:17:00.000-08:00

logwatch - system log analyzer and reporter

--detail level 10/5/0              (high, med, low)
--debug level   0/1/..100
--service service-name/all          (more , seperated )
--print                             (Print output on screen)
--save /usr/mylogwatch_`date +%d-%b-%Y`
--mailto shirish@server.example.com
--range Yesterday/Today/all/Help
--archives                          (logwatch searches archived too like messages.1 etc..)
--logdir /var/op/logs/              (Locate your log dirs)

Config FILES (Source REDHAT)
       /usr/share/logwatch/
              This directory contains all the perl executables and configuration files shipped with
              the logwatch distribution.

       /etc/logwatch
              This directory contains local configuration files that override the default configura-
              tion. See MORE INFORMATION below for more information.
EXAMPLES
       logwatch --service ftpd-xferlog --range all --detail high --print --archives
              This will print out all FTP transfers that are stored in all current and archived xfer-
              logs.
       logwatch --service pam_pwdb --range yesterday --detail high --print
              This will print out login information for the previous day...

range
   --range today
   --range yesterday
   --range '4 hours ago for that hour'
   --range '-3 days'
   --range 'since 2 hours ago for those hours'
   --range 'between -10 and -2 days'
   --range 'Apr 15, 2005'
   --range 'first Monday in May'
   --range 'between 4/23/2005 and 4/30/2005'
   --range '2005/05/03 10:24:17 for that second'

# Faced any problem Feedback in above contact me
#============================Scratch===============================#
#                                                     AND Many More .....................Linux is Endless               #
#========================== Hope you Liked IT =========================#
#                                                                              CMND LOGRATATE-- BY Shirish Shukla #
#                                                                                                             RHC Engineer 2010 #
#                                                                                                           shirish.linux@gmail.com #
#                                                                                                         shirishlinux.blogspot.com #
#                         "Give Respect To Time One Day At Right Time, Time Will Respect You" #
#==================================================================#
#                          TRy Hard theres nothing that are un-achievable by HARDdd-WORKkk #
#==================================================================#

change date and time linux

2011-01-27T08:09:00.000-08:00

change date and time linux

============ Treating with date command =================

1> date 081811002007 [mmddhhmmyyyy]--To set the Linux clock to 11th-Aug-2007-11-AM
2> timeconfig --Set your TIMEZONE
3> hwclock --hc to sys--->-->To set the Linux[system]clock from the HW clock
4> hwclock --utc sys to hc -->To set the HWclock from the Linux[system] clock

touch -t yyyymmddhhmm filename

echo "DATE:" `date --date "today" +%d-%m-%Y`             <--DATE:20-12-2010
echo "DATE:" `date --date "yesterday" +%d-%m-%Y`
echo "DATE:" `date --date "+5 minutes ago" +%d-%m-%Y-%M` <--present -5 min
echo "DATE:" `date --date "-5minutes ago" +%d-%m-%Y-%M` <---Present +5 min
echo "DATE:" `date --date "1 month ago -5 minutes ago" +%d-%m-%Y-%M`
                                                         <--present -1 month +5 min

Some importnat journal use paramiters
%a --> Mon
%b --> Jan
%d --> date 01..31      %e --> 1..31
%H --> hour 0..23)      %k --> 1..23
%M --> minute (00..59)
%S --> Seconds(00..60)
%I --> hour 00..12)     %m --> 1-12
%Y --> year 2010        %y --> year 10(last 2 digit)
%p --> AM-PM            %p --> am-pm
%T --> %H:%M:%S

=================================== More n more ==================
%%--->a literal %
%a--->localeâs abbreviated weekday name (e.g., Sun)
%A--->localeâs full weekday name (e.g., Sunday)
%b--->localeâs abbreviated month name (e.g., Jan)
%B--->localeâs full month name (e.g., January)
%c--->localeâs date and time (e.g., Thu Mar 3 23:05:25 2005)
%C--->century; like %Y, except omit last two digits (e.g., 21)
%d--->day of month (e.g, 01)
%D--->date; same as %m/%d/%y
%e--->day of month, space padded; same as %_d
%F--->full date; same as %Y-%m-%d
%g--->last two digits of year of ISO week number (see %G)
%G--->year of ISO week number (see %V); normally useful only with %V
%h--->same as %b
%H--->hour (00..23)
%I--->hour (01..12)
%j--->day of year (001..366)
%k--->hour ( 0..23)
%l--->hour ( 1..12)
%m--->month (01..12)
%M--->minute (00..59)
%n--->a newline
%N--->nanoseconds (000000000..999999999)
%p--->localeâs equivalent of either AM or PM; blank if not known
%P--->like %p, but lower case
%r--->localeâs 12-hour clock time (e.g., 11:11:04 PM)
%R--->24-hour hour and minute; same as %H:%M
%s--->seconds since 1970-01-01 00:00:00 UTC
%S--->second (00..60)
%t--->a tab
%T--->time; same as %H:%M:%S
%u--->day of week (1..7); 1 is Monday
%U--->week number of year, with Sunday as first day of week (00..53)
%V--->ISO week number, with Monday as first day of week (01..53)
%w--->day of week (0..6); 0 is Sunday
%W--->week number of year, with Monday as first day of week (00..53)
%x--->localeâs date representation (e.g., 12/31/99)
%X--->localeâs time representation (e.g., 23:13:48)
%y--->last two digits of year (00..99)
%Y--->year
%z--->+hhmm numeric timezone (e.g., -0400)
%:z   -> +hh:mm numeric timezone (e.g., -04:00)
%::z -> +hh:mm:ss numeric time zone (e.g., -04:00:00)
%:::z -> numeric time zone with : to necessary precision (e.g., -04, +05:30)
%Z    -> alphabetic time zone abbreviation (e.g., EDT)

### Other usefull operation with date command
# date --date="next Monday"
# date --date="10 days ago"

##### Yesterday
# date --date="yesterday"   --OR--
# date --date="-1 day"

##### Tomorrow
# date --date="next day"      --OR--
# date --date="-1 days ago"
# date --date='tomorrow'

##### After n Day/week/month/year
# date --date='101 day'
# date --date='101 week'
# date --date='101 month'
# date --date='101 year'

### Similarly Before n Day/week/month/year Ago
# date --date='101 day ago'
# date --date='101 week ago'
# date --date='101 month ago'
# date --date='101 year ago'

##### 10 hours ago
# date --date='10 hour ago'
##### After 10 hours
# date --date='10 hour'   --OR--
# date --date=-'10 hour ago'     <-- Same applicable for all
##### 10 minutes ago
# date --date='10 minutes ago'
##### 10 seconds ago
# date --date=-'10 seconds ago'

##### Print date after 1 day 5 hour
# date --date='1 day 5 hour'

# date --date='-1 day -5 hour ago'

# Faced any problem Feedback in above contact me
#============================Scratch==============================#
#                                                     AND Many More .....................Linux is Endless               #
#========================== Hope you Liked IT =======================#
#                                                                                          CMDS DATE-- BY Shirish Shukla #
#                                                                                                                RHC Engineer 2010 #
#                                                                                                           shirish.linux@gmail.com #
#                                                                                                         shirishlinux.blogspot.com #
#                          "Give Respect To Time One Day At Right Time, Time Will Respect You" #
#==================================================================#
#                          TRy Hard theres nothing that are un-achievable by HARDdd-WORKkk #
#==================================================================#

Linux Unix Help SHIRISH SHUKLA

Setup SUSE Local Repository

System Authentication via LDAP server

Do following seps at LDAP server: server.shirish.com end

Above I will cover in coming blog .. keep learning .. have a great day . --Shirish Shukla

Script to print partition utilization - HP-UX

Create filesystem in a partition

> Shirish Shukla

Diff file1 file2

Script : diff.pl

> Shirish Shukla

ConverT Shell Script to C - Binary [executable ]

Script to calculate Expiry Date

File: expire-date.sh

## How to USE

HP-UX Basic Admin -3 - Software and imp log files

HP-UX Basic Admin -2 - Basic Admins

HP-UX Basic Admin -1 - Sys Info

backup using script imp files linux

> Shirish Shukla

Monitor Your System Performance

IMP Linux Services

Diff ext2 ext3 ext4

File Permission Linux

Types of Processes in linux

how a normal user update shadow file on password change

ssh without password

Script to take MBR backup

Install Configure Nagios

mysql master -slave Replication

boot process Linux sort

LINUX INTERVIEW QUESTIONS

"TELL ME SOMETHING ABOUT YOUR SELF"

LOGWATCH LINUX

change date and time linux

Above I will cover in coming blog .. keep learning .. have a great day .

--Shirish Shukla