Sys Admin

CEPH bluestore using ceph-ansible

2017-04-21T00:53:00.001-07:00

Just to test the ceph bluestore i have created 2 virtual machine in virtualbox with hostname: admin & osd1.

Attached the 2 10G hdd for the OSD's in both the nodes.

Below are the commands that i used to deploy it using the ceph-ansible:

git clone https://github.com/ceph/ceph-ansible
cd ceph-ansible
cp group_vars/osds.yml.sample group_vars/osds.yml
cp group_vars/all.yml.sample group_vars/all.yml
cp group_vars/mons.yml.sample group_vars/mons.yml
cp site.yml.sample site.yml

vi group_vars/osds.yml
devices:
- /dev/sdb
- /dev/sdc
bluestore : true

vi group_vars/all.yml
ceph_stable: true
ceph_mirror: http://download.ceph.com/
ceph_stable_key: https://download.ceph.com/keys/release.asc
ceph_stable_release: kraken
ceph_stable_repo: "{{ ceph_mirror }}/rpm-{{ ceph_stable_release }}"

monitor_interface: enp0s3
monitor_address: 192.xx.xx.xx
osd_objectstore: bluestore

ceph_conf_overrides:
global:
enable experimental unrecoverable data corrupting features: 'bluestore rocksdb'
bluestore fsck on mount: true
bluestore block db size: 67108864
bluestore block wal size: 134217728
bluestore block size: 5368709120

ansible-playbook site.yml

If you don't get any error during installation , you will see the below output when your cepph cluster is UP:

[root@admin ~]# ceph osd tree
2017-04-21 13:11:00.775650 7f01ea92c700 -1 WARNING: the following dangerous and experimental features are enabled: bluestore,rocksdb
2017-04-21 13:11:00.851519 7f01ea92c700 -1 WARNING: the following dangerous and experimental features are enabled: bluestore,rocksdb
ID WEIGHT TYPE NAME UP/DOWN REWEIGHT PRIMARY-AFFINITY
-1 0.01959 root default
-2 0.00980 host osd1
1 0.00490 osd.1 up 1.00000 1.00000
2 0.00490 osd.2 up 1.00000 1.00000
-3 0.00980 host admin
0 0.00490 osd.0 up 1.00000 1.00000
3 0.00490 osd.3 up 1.00000 1.00000
[root@admin ~]# ceph -s
2017-04-21 13:11:09.506583 7fef54404700 -1 WARNING: the following dangerous and experimental features are enabled: bluestore,rocksdb
2017-04-21 13:11:09.531409 7fef54404700 -1 WARNING: the following dangerous and experimental features are enabled: bluestore,rocksdb
cluster 4925dc3b-b43a-4766-81d4-584ba5755366
health HEALTH_OK
monmap e2: 1 mons at {admin=192.168.104.141:6789/0}
election epoch 12, quorum 0 admin
mgr no daemons active
osdmap e67: 4 osds: 4 up, 4 in
flags sortbitwise,require_jewel_osds,require_kraken_osds
pgmap v158: 0 pgs, 0 pools, 0 bytes data, 0 objects
99072 kB used, 20383 MB / 20480 MB avail

[root@admin ~]# lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda 8:0 0 21.7G 0 disk
├─sda1 8:1 0 500M 0 part /boot
└─sda2 8:2 0 21.2G 0 part
├─centos-root 253:0 0 19.2G 0 lvm /
└─centos-swap 253:1 0 2G 0 lvm [SWAP]
sdb 8:16 0 10G 0 disk
├─sdb1 8:17 0 100M 0 part /var/lib/ceph/osd/ceph-0
└─sdb2 8:18 0 5G 0 part
sdc 8:32 0 10G 0 disk
├─sdc1 8:33 0 100M 0 part /var/lib/ceph/osd/ceph-3
└─sdc2 8:34 0 5G 0 part

Solved : Unable to lock the administration directory (/var/lib/dpkg/)

2016-05-31T22:44:00.002-07:00

Delete the lock file using below command:

sudo rm /var/lib/apt/lists/lock

sudo rm /var/cache/apt/archives/lock

now you can install package using apt-get command.

Install Scala in CentOS 6

2015-09-08T23:48:00.005-07:00

Installation of Scala

Steps :

wget http://downloads.typesafe.com/scala/2.11.1/scala-2.11.1.tgz
tar xvf scala-2.11.1.tgz
sudo mvscala-2.11.1/usr/lib
sudo ln-f-s/usr/lib/scala-2.11.1/usr/lib/scala

Configuration of Scala in CentOS

Add to PATH,

edit /etc/profile.d/scala.sh
export PATH=$PATH:/usr/lib/scala/bin source /etc/profile.d/scala.sh
$ scala -version
Scala code runner version 2.11.1 -- Copyright 2002-2013, LAMP/EPFL

Note :
for future ref:
substitute the latest release by visiting http://www.scala-lang.org/download/all.html, click on the latest release and scroll down to “Other resources”. There you’ll find the Max OS X, Unix, Cygwin version .tgz file. Right click and copy the url to your clipboard and use it in your wget [right-click-paste].

Start wildfly service with standalone-full.xml

2015-09-08T23:42:00.001-07:00

Wildfly provides a service.bat in %WILDFLY_HOME%\bin\service. Calling the batch file with the install parameter installs Wildfly as a service on Windows. Once it is installed on windows, you can change the settings so that wildfly starts all the modules and services instead of default minimal setup. For this, change standalone.bat file and add this line :

set "SERVER_OPTS=--server-config=standalone-full.xml"

This will enable startup of all modules & services of wildfly from now on.

Scan FC LUN's in RHEL/CentOS

2015-02-03T21:39:00.000-08:00

1.First find out how many disks are visible in “fdisk -l” .

# fdisk -l 2>/dev/null | egrep '^Disk' | egrep -v 'dm-' | wc -l

2.Find out how many host bus adapter configured in the Linux box.you can use “systool -fc_host -v” to verify available FC in the system.

# ls /sys/class/fc_host
host0  host1

In this case,you need to scan host0 & host1 HBA.

3.If the system virtual memory is too low ,then do not proceed further.If you have enough free virtual memory,then you can proceed with below command to scan new LUNS.

# echo "1" > /sys/class/fc_host/host0/issue_lip
# echo "1" > /sys/class/fc_host/host1/issue_lip

Note: You need to monitor the “issue_lip” in /var/log/messages to determine when the scan will complete.This operation is an asynchronous operation.

4.Verify if the new LUN is visible or not by counting the available disks.

# fdisk -l 2>/dev/null | egrep '^Disk' | egrep -v 'dm-' | wc -l

If any new LUNS added ,then you can see more count is more then before scanning the LUNS.

Source: http://www.unixarena.com/

List all files & Folders In Windows/Unix

2015-02-03T20:41:00.001-08:00

On Windows CMD Prompt:

dir /s /b /o:gn

On UNIX :

find . -print | sed 's;[^/]*/;|___;g;s;___|; |;g'

How to enable federated engine in MySQL

2015-01-06T01:17:00.003-08:00

[root@srvcob etc]# mysql -h localhost -u root -p
Enter password:
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 3
Server version: 5.1.52 Source distribution

Copyright (c) 2000, 2010, Oracle and/or its affiliates. All rights reserved.
This software comes with ABSOLUTELY NO WARRANTY. This is free software,
and you are welcome to modify and redistribute it under the GPL v2 license

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql> show engines;
+------------+---------+------------------------------------------------------------+--------------+------+------------+
| Engine     | Support | Comment                                                    | Transactions | XA   | Savepoints |
+------------+---------+------------------------------------------------------------+--------------+------+------------+
| MRG_MYISAM | YES     | Collection of identical MyISAM tables                      | NO           | NO   | NO         |
| CSV        | YES     | CSV storage engine                                         | NO           | NO   | NO         |
| MyISAM     | DEFAULT | Default engine as of MySQL 3.23 with great performance     | NO           | NO   | NO         |
| InnoDB     | YES     | Supports transactions, row-level locking, and foreign keys | YES          | YES  | YES        |
| MEMORY     | YES     | Hash based, stored in memory, useful for temporary tables  | NO           | NO   | NO         |
+------------+---------+------------------------------------------------------------+--------------+------+------------+
5 rows in set (0.00 sec)

mysql> install plugin federated soname 'ha_federated.so';
Query OK, 0 rows affected, 1 warning (0.01 sec)

mysql> show engines;
+------------+---------+------------------------------------------------------------+--------------+------+------------+
| Engine     | Support | Comment                                                    | Transactions | XA   | Savepoints |
+------------+---------+------------------------------------------------------------+--------------+------+------------+
| FEDERATED  | NO      | Federated MySQL storage engine                             | NULL         | NULL | NULL       |
| CSV        | YES     | CSV storage engine                                         | NO           | NO   | NO         |
| MyISAM     | DEFAULT | Default engine as of MySQL 3.23 with great performance     | NO           | NO   | NO         |
| InnoDB     | YES     | Supports transactions, row-level locking, and foreign keys | YES          | YES  | YES        |
| MEMORY     | YES     | Hash based, stored in memory, useful for temporary tables  | NO           | NO   | NO         |
| MRG_MYISAM | YES     | Collection of identical MyISAM tables                      | NO           | NO   | NO         |
+------------+---------+------------------------------------------------------------+--------------+------+------------+
6 rows in set (0.00 sec)

mysql>

And then, edit your /etc/my.cnf and put the word federated in [mysqld] sector:
 [mysqld]
    datadir=/var/lib/mysql
    socket=/var/lib/mysql/mysql.sock
    user=mysql
    # Disabling symbolic-links is recommended to prevent assorted security risks
    symbolic-links=0
    federated

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

And then:

service mysqld restart

mysql> show engines;
+------------+---------+------------------------------------------------------------+--------------+------+------------+
| Engine     | Support | Comment                                                    | Transactions | XA   | Savepoints |
+------------+---------+------------------------------------------------------------+--------------+------+------------+
| FEDERATED  | YES     | Federated MySQL storage engine                             | NO           | NO   | NO         |
| CSV        | YES     | CSV storage engine                                         | NO           | NO   | NO         |
| MyISAM     | DEFAULT | Default engine as of MySQL 3.23 with great performance     | NO           | NO   | NO         |
| InnoDB     | YES     | Supports transactions, row-level locking, and foreign keys | YES          | YES  | YES        |
| MEMORY     | YES     | Hash based, stored in memory, useful for temporary tables  | NO           | NO   | NO         |
| MRG_MYISAM | YES     | Collection of identical MyISAM tables                      | NO           | NO   | NO         |
+------------+---------+------------------------------------------------------------+--------------+------+------------+
6 rows in set (0.00 sec)

mysql>

Check the physical status of an Ethernet port in Linux

2014-09-26T01:43:00.000-07:00

Using in-built command :

root@abcd~# ethtool <ethX>

for eg:

root@abcd~# ethtool eth0

Settings for eth0:
        Supported ports: [ TP ]
        Supported link modes:   10baseT/Half 10baseT/Full
                                100baseT/Half 100baseT/Full
                                1000baseT/Full
        Supports auto-negotiation: Yes
        Advertised link modes:  10baseT/Half 10baseT/Full
                                100baseT/Half 100baseT/Full
                                1000baseT/Full
        Advertised pause frame use: No
        Advertised auto-negotiation: Yes
        Speed: 1000Mb/s
        Duplex: Full
        Port: Twisted Pair
        PHYAD: 1
        Transceiver: internal
        Auto-negotiation: on
        MDI-X: on
        Supports Wake-on: pumbg
        Wake-on: g
        Current message level: 0x00000001 (1)
        Link detected: yes

check the last line if it shows yes then that ethernet port is up.

OR

root@abcd~# dmesg | grep eth

device eth2 entered promiscuous mode
igb: eth2 NIC Link is Up 1000 Mbps Full Duplex, Flow Control: RX/TX
ADDRCONF(NETDEV_CHANGE): eth2: link becomes ready

Enable Remote Admin Glassfish

2014-05-19T02:50:00.000-07:00

GlassFish 3.1.2+ does not allow remote administration out-of-the-box. To activate remote administration you will have to set an admin password before performing the actual enabling:


asadmin change-admin-password --domain_name [DOMAIN_NAME]
asadmin enable-secure-admin --port [PORT_NAME]

JRE in Chrome CentOS 6.4

2013-08-29T00:51:00.001-07:00

Just link libnpjp2.so which is in <your-java-dir>/lib/i386 to/opt/google/chrome/plugins .

For me, here are the commands:

mkdir /opt/google/chrome/plugins
cd /opt/google/chrome/plugins
ln -s /usr/local/jre1.6.0_17/lib/i386/libnpjp2.so .

Restart Chrome and enjoy!

Completely Re-install Apache2 on Ubuntu

2013-05-28T05:44:00.002-07:00

Find and drop all Apache packages:

APACHE_PKGS=`sudo dpkg --get-selections | grep apache | cut -f 1`
# Make sure things are sane:
echo $APACHE_PKGS
# Example output: apache2 apache2-mpm-prefork apache2-utils apache2.2-common \
# libapache2-mod-php5 libapache2-mod-python libapache2-svn
# Likely if you have a Python application:
# libapache2-mod-python libapache2-mod-python-doc libapache2-mod-wsgi
# Or if you roll with the PHP: 
# libapache2-mod-php5
sudo apt-get remove --purge $APACHE_PKGS

Re-install Apache

# You might want to consider not re-installing the whole list;
# instead dump it out, audit, and install what you need:
sudo apt-get install $APACHE_PKGS

After this, all the configuration files were back, and I had a default Apache install.

Create Bulk folders Using Batch file

2013-04-01T03:03:00.000-07:00

Simple Script To Create Bulk Folder L:isted In Text File:

Create a file named "CreateDir.bat" and list all the folders tat you want to create in "file.txt"

Content of CreateDir.bat

@echo off

for /f %%i in (file.txt) do mkdir %%i

Simply run the batch file and your folders will be created.!

HowTO: Install Postfix & dovecot On CentOS 6

2013-03-15T05:27:00.000-07:00

How to installing Postfix and Dovecot on Linux CentOS

yum install postfix dovecot
chkconfig postfix on
chkconfig dovecot on

Configure main.cf :

vi /etc/postfix/main.cf
# change or add on these line:

myhostname = mail.fileregion.com
mydomain = fileregion.com
myorigin = $mydomain
inet_interfaces = all
mydestination = $myhostname, localhost.$mydomain, localhost, $mydomain
mynetworks = 127.0.0.0/8
home_mailbox = Maildir/
smtpd_sasl_type = dovecot
smtpd_sasl_path = private/auth
smtpd_sasl_auth_enable = yes
smtpd_recipient_restrictions = permit_mynetworks, permit_sasl_authenticated, reject_unauth_destination, permit
broken_sasl_auth_clients = yes

Restarting postfix:

/etc/init.d/postfix restart

Configure Dovecot on Linux CentOS 6

Configure dovecot.conf:

vi /etc/dovecot/dovecot.conf

# uncomment on this line:
protocols = imap pop3
listen = *
Config mail auth mehanism:

vi /etc/dovecot/conf.d/10-auth.conf
# change on these line:

disable_plaintext_auth = no
auth_mechanisms = plain login
Configure mail_location:

vi /etc/dovecot/conf.d/10-mail.conf
# change / uncomment on this line:
mail_location = maildir:~/Maildir

Configure service auth:

vi /etc/dovecot/conf.d/10-master.conf
# commented on these line:
#unix_listener auth-userdb {
#mode = 0600
#user =
#group =
#}
# change or setup on these line:
# Postfix smtp-auth
unix_listener /var/spool/postfix/private/auth {
mode = 0666
user = postfix
group = postfix
}

Configure POP3:

vi /etc/dovecot/conf.d/20-pop3.conf
# uncomment on these line:
pop3_uidl_format = %08Xu%08Xv
pop3_client_workarounds = outlook-no-nuls oe-ns-eoh

Restaring Dovecot :

/etc/init.d/dovecot restart

HowTO: Install VNC Server On CentOS 6.3

2013-03-15T04:44:00.000-07:00

1. Install Tigervnc Server

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[root@demo ~]# yum -y install tigervnc-server  

2. Install X Windows and GNOME.

This used to be yum groupinstall "X Window System" "GNOME Desktop Environment", but is now simply:

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yum groupinstall "X Window System" "Desktop"  

3. Create a user (or use and existing user) and create VNC login.

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[root@demo ~]# useradd david  
[root@demo ~]# passwd david  
Changing password for user david.  
New password:  
Retype new password:  
passwd: all authentication tokens updated successfully.  
[root@demo ~]# su - david  

4. Switch to the user (su - user) and issue 'vncpasswd' to set the VNC password

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[david@demo ~]$ vncpasswd  
Password:  
Verify:  
[david@demo ~]$  

5. Start VNC using 'vncserver :1'

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[david@demo ~]$ vncserver :1  
xauth:  creating new authority file /home/david/.Xauthority  
  
New 'demo.domain.net:1 (david)' desktop is demo.domain.net:1  
  
Creating default startup script /home/david/.vnc/xstartup  
Starting applications specified in /home/david/.vnc/xstartup  
Log file is /home/david/.vnc/demo.domain.net:1.log  
  
[david@demo ~]$  

6. Stop VNC using using 'vncserver -kill :1'

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[david@demo ~]$ vncserver -kill :1  

7. Setting resolution:

In /etc/sysconfig/vncservers, add a line for each user.

NOTE: if you if you need to install Oracle software, use geometry 1024x768.

You can also do this via the shell using: vncserver :1 -geometry 1024x768 -depth xx

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# The VNCSERVERS variable is a list of display:user pairs.  
#  
# Uncomment the lines below to start a VNC server on display :2  
# as my 'myusername' (adjust this to your own).  You will also  
# need to set a VNC password; run 'man vncpasswd' to see how  
# to do that.    
#  
# DO NOT RUN THIS SERVICE if your local area network is  
# untrusted!  For a secure way of using VNC, see this URL:  
# http://kbase.redhat.com/faq/docs/DOC-7028  
 
# Use "-nolisten tcp" to prevent X connections to your VNC server via TCP.  
 
# Use "-localhost" to prevent remote VNC clients connecting except when  
# doing so through a secure tunnel.  See the "-via" option in the  
# `man vncviewer' manual page.  
 
# VNCSERVERS="2:myusername"  
# VNCSERVERARGS[2]="-geometry 800x600 -nolisten tcp -localhost"  
VNCSERVERS="1:david"  
VNCSERVERARGS[1]="-geometry 1024x768"  

For multiple users, simply add the user to the VNCSERVERS list and add a VNCSERVERARGS[x] entry.

So for three users:

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VNCSERVERS="1:david 2:bill 3:john"  
VNCSERVERARGS[1]="-geometry 1024x768"  
VNCSERVERARGS[2]="-geometry 1024x768"  
VNCSERVERARGS[3]="-geometry 640x480"  

8. Open the port for the user, in this case 5801.

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-A INPUT -m state --state NEW -m tcp -p tcp --dport 5801 -j ACCEPT  

Save and restart IP Tables (/etc/init.d/iptables save | restart)

Source: http://www.davidghedini.com/pg/entry/vnc_server_on_centos_6

Change Static IP to DHCP in CentOS 6

2013-03-07T01:38:00.000-08:00

Setting up a Linux for dhcp can be done by editing file using a text editor such as vi:
# vi /etc/sysconfig/network-scripts/ifcfg-eth0
Following is sample static configuration:

DEVICE=eth0
BOOTPROTO=static
HWADDR=00:19:D1:2A:BA:A8
IPADDR=10.10.10.10
NETMASK=255.255.255.0
ONBOOT=yes

Replace static configuration with DHCP:

DEVICE=eth0
BOOTPROTO=dhcp
HWADDR=00:19:D1:2A:BA:A8
ONBOOT=yes

Save and close the file. Just restart network service:

Change MAC Address In Linux

2013-03-05T03:30:00.000-08:00

Here we will see a technique how to spoof MAC address in Linux. MAC address spoofing is changing the Media Access Control (MAC) address of the network interface card (NIC).

First of all let me tell you that the MAC address or the Hardware address is inbuilt and is actually burnt into your NIC interface card at the time of manufacturing. It is unique worldwide and cannot be changed permanently by the use of any kind of software.

That being said, however we can change it temporarily to suit our needs. The method described here can be used in RHEL, CentOS and Ubuntu as well.

MAC address is 48 bits hexadecimal address. Before directly changing the address you need to find out the current MAC address of your network card by using the command

# ifconfig | grep HWADDR

It will give you output as

eth0 Link encap:Ethernet HWaddr 00:21:5A:9B:00:F0

The MAC address in this case is 00:21:5A:9B:00:F0

How to spoof / change MAC address in Linux

To change it use the ifconfig command as below

# ifconfig eth0 down
# ifconfig eth0 hw ether 00:21:5A:9B:00:F2
# ifconfig eth0 up

Note that we have changed the new MAC address to 00:21:5A:9B:00:F2. Now if you check you’ll see the newly assigned address as your MAC address.

# ifconfig | grep HWADDR
eth0 Link encap:Ethernet HWaddr 00:21:5A:9B:00:F2

You can choose any 48 bit hexadecimal address as your new MAC address. After changing your MAC address everyone communicating with you will see the new address as your MAC address.

As I’ve told earlier this is not permanent and it will revert back to your old address as soon you reboot your machine.

Useful Windows 8 Keyboard Shortcuts

2013-03-04T22:54:00.000-08:00

Some useful windows 8 keyboard shortcuts:

Shortcut	Description
+ D	Show Desktop
+ C	Open Charms Menu
+ F	Charms Menu – Search
+ H	Charms Menu – Share
+ K	Charms Menu – Devices
+ I	Charms Menu – Settings
+ Q	Search For Installed Apps
+ W	Search Settings
+ Tab	Cycle through open Modern UI Apps
+ Shift + Tab	Cycle through open Modern UI Apps in reverse order
+ .	Snaps app to the right (split screen multitasking)
+ Shift + .	Snaps app to the left (split screen multitasking)
+ ,	Temporarily view desktop
Alt + F4	Quit Modern UI Apps
+ E	Launch Windows Explorer Window
+ L	Lock PC and go to lock screen
+ T	Cycle through icons on taskbar (press Enter to launch app)
+ X	Show Advanced Windows Settings Menu
+ E	Launch Windows Explorer Window
+ Page Down	Moves Start screen and apps to secondary monitor on the right
+ M	Minimize all Windows
+ Shift + M	Restore all minimized Windows
+ R	Open Run dialog box
+ Up Arrow	Maximize current window
+ Down Arrow	Minimize current window
+ Left Arrow	Maximize current window to left side of the screen
+ Right Arrow	Maximize current window to right side of the screen
Ctrl + Shift + Escape	Open Task Manager
+ Print Screen	Takes a Print Screen and saves it to your Pictures folder
+ Page Up	Moves Start screen and apps to secondary monitor on the left
+ Pause Break	Display System Properties
Shift + Delete	Permanently delete files without sending it to Recycle Bin
+ F1	Open Windows Help and Support
+ V	Cycle through notifications
+ Shift + V	Cycle through notifications in reverse order
+ 0 to 9	Launch/show app pinned to taskbar at indicated number
+ Shift + 0 to9	Launch new instance of app pinned to taskbar at indicated number
Alt + Enter	Display Properties of selected item in File Explorer
Alt + Up Arrow	View upper level folder of current folder in File Explorer
Alt + Right Arrow	View next folder in File Explorer
Alt + Left Arrow	View previous folder in File Explorer
+ P	Choose secondary display modes
+ U	Open Ease of Access Center
Alt + Print Screen	Print Screen focused Window only
+ Spacebar	Switch input language and keyboard layout
+ Shift +Spacebar	Switch to previous input language and keyboard layout
+ Enter	Open Narrator
+ +	Zoom in using Magnifier
+ -	Zoom out using Magnifier
+ Escape	Exit Magnifier

New XAMPP security concept Error

2013-02-18T23:39:00.002-08:00

I Installed Xampp on CENTOS 6.2 and while accessing PHPmyadmin got the following error:
New XAMPP security concept:Access to the requested object is only available from the local network.
This setting can be configured in the file "httpd-xampp.conf".

If you think this is a server error, please contact the webmaster.Error 403
localhost

Solution:
1) Open httpd-xampp.conf which is at /opt/lampp/etc/extra/
2) Find <Directory "/opt/lampp/phpmyadmin">
3) Now just add Require all granted before </Directory>
4) So the code will look like this
<Directory "/opt/lampp/phpmyadmin">

  AllowOverride AuthConfig Limit
  Order allow,deny
  Allow from all
  Require all granted
</Directory>

4) Now finally Restart the xampp with this command /opt/lampp/lampp restart

If error persists then :

your-xampppath\apache\conf\extra open file= httpd-xampp.conf and fint the below tag

# Close XAMPP sites here
<LocationMatch "^/(?i:(?:xampp|licenses|phpmyadmin|webalizer|server-status|server-info))">
    Order deny,allow
    Deny from all
    Allow from ::1 127.0.0.0/8 
    ErrorDocument 403 /error/HTTP_XAMPP_FORBIDDEN.html.var
</LocationMatch>

and add

"Allow from all"

after Allow from ::1 127.0.0.0/8 {line}

restart xampp and you are done !!!!

How to Verify a Linux is 32-Bit or 64-Bit?

2013-01-03T22:02:00.003-08:00

To verify if a system is 32 bit versus 64 bit you can use the uname command. Below are examples of using the uname command from the CLI on a 32 bit system followed by using the uname command on a 64 bit system.

32 Bit CentOS Linux Server

1[root@server ~]# uname -a

2Linux server1.example.com 2.6.18-92.1.13.el5 #1 SMP Wed Sep 24 19:33:52 EDT 2008 i686 i686 i386 GNU/Linux

64 Bit CentOS Linux Server

1[root@server ~]# uname -a

2Linux server.example.com 2.6.18-53.1.21.el5 #1 SMP Tue May 20 09:35:07 EDT 2008 x86_64 x86_64 x86_64 GNU/Linux

As you can see above the 64 bit server will show x86_64 numerous times after the install date and time. The 32 bit system will show i686 and i386 after the install date and time. So it is very easy to verify if a system is 32 bit versus 64 bit using the “uname -a” command from a shell.

Reset MySql Root Password

2012-10-12T03:01:00.006-07:00

One of the very worst scenarios for a system administrator is when they forget a password for the root account. That is the same case when a Database admin does the same for the root account for Mysql Database. So to help here, these are the following steps which one can perform to recover the root password back for Mysql database.

Stop Mysql Server:

$ sudo /etc/init.d/mysql stop

Then, start the mysql server with skip-grant-tables options. –skip-grant-tables option will force the mysql process not to read the user table into memory, so that when you try to login to the Mysql server, it won’t ask for the password.

$ sudo mysqld_safe --skip-grant-tables  &

This command is very dangerous if you Mysql server is connected to the network. While you are recovering your password, someone can login to your server remotely and do whatever he/she wants. To keep that safe, start your server with “–skip-networking” option, which will not open a network port for the server

$ mysqld_safe --skip-grant-tables --skip-networking &

Now connect to mysql server using mysql client without giving any password

$ mysql -u root -p

Now setup the new password for the root user:

mysql> use mysql;

mysql> update user set password=PASSWORD("NEWPASSWORD") where user="root";

mysql> flush privileges;

mysql> Ctrl+D

Now stop the mysql server

$ sudo /etc/init.d/mysql stop

Now start the mysql server normally, so that it could read the password information.

$ sudo /etc/init.d/mysql start

Installing Sun JAVA in Ubuntu

2012-08-24T04:57:00.003-07:00

Step by step:

Download JDK from Sun/Oracle. Choose bin version (not rpm). The file would be in form of jdk-version-platform.bin (in my case it was: jdk-6u25-linux-x64.bin )
Add execution rights to the downloaded file

$ chmod u+x jdk-6u25-linux-x64.bin
Execute script. It will unpack its content to current directory (press Enter when asked)

$ ./jdk-6u25-linux-x64.bin
Now you should have directory i.e. jdk1.6.0_25/ with JDK files in it.
Move unpacked JDK to final destination e.g. /opt/java/

$ sudo mv jdk1.6.0_25/ /opt/java/
Create symbolic link to that directory that will represent this JDK in general regardless current version. It will ease the future updates of JDK. I can any name. I have chosen sun-java6-manual

$ cd /opt/java/
$ sudo ln -s jdk1.6.0_25 sun-java6-manual
Now create another symbolic link in /usr/lib/jvm pointing to previous one.

$ cd /usr/lib/jvm/
$ sudo ln -s /opt/java/sun-java6-manual
I assume that you have already installed Sun JDK from Ubuntu repositories before. If this is the case then there should be .java-6-sun.jinfo file in/usr/lib/jvm/ directory. We will copy that file and modify it. If there is no such file you can download it to current directory with this command:

$ sudo apt-get -d install sun-java6-bin && find /var/cache/apt/archives/ -iname sun-java6-bin* -exec ar -p '{}' data.tar.gz \; | tar -zxO ./usr/lib/jvm/.java-6-sun.jinfo | sudo tee .java-6-sun.jinfo

You can delete it afterwards. The reason I am not using .java-6-openjdk.jinfofile that probably is present in your Ubuntu installation is that it is slightly different that Sun’s one (some browser plugin entries are missing).

Copy file and replace path entries that they point to created link in /usr/lib/jvm/

$ sudo sed s/java-6-sun/sun-java6-manual/ .java-6-sun.jinfo | sudo tee .sun-java6-manual.jinfo
Now edit the beginning of file so it looks like below:

$ sudo vim .sun-java6-manual.jinfo

name=sun-java6-manual
alias=sun-java6-manual
priority=30

Choose whatever priority you like.
Now we have to register new alternatives in update-alternatives mechanism.

$ cat .sun-java6-manual.jinfo | grep -E '^(jre|jdk)' | awk '{print "/usr/bin/" $2 " " $2 " " $3 " 30 \n"}' | xargs -t -n4 sudo update-alternatives --verbose --install
Do the same with plugins

$ sudo update-alternatives --verbose --install /usr/lib/mozilla/plugins/libjavaplugin.so mozilla-javaplugin.so /usr/lib/jvm/sun-java6-manual/jre/lib/amd64/libnpjp2.so 30

$ sudo update-alternatives --verbose --install /usr/lib/xulrunner-addons/plugins/libjavaplugin.so xulrunner-1.9-javaplugin.so /usr/lib/jvm/sun-java6-manual/jre/lib/amd64/libnpjp2.so 30
Now we are ready to switch default Java to the new one.

$ update-java-alternatives -l
It should list available java alternatives. It may look like:

java-6-openjdk 1061 /usr/lib/jvm/java-6-openjdk
java-6-sun 63 /usr/lib/jvm/java-6-sun
sun-java6-manual 1500 /usr/lib/jvm/sun-java6-manual
Set chosen option with:

$ sudo update-java-alternatives -s sun-java6-manual
Now confirm that java command is the new installed one

$ java -version
java version "1.6.0_25"
Java(TM) SE Runtime Environment (build 1.6.0_25-b06)
Java HotSpot(TM) 64-Bit Server VM (build 20.0-b11, mixed mode)

How to Back Up and Restore NTFS and Share Permissions Using ICACLS

2012-08-03T05:07:00.002-07:00

To save:

D:\>icacls D:\acltest /save perms.txt /t /c
processed file: D:\acltest
processed file: D:\acltest\Screens
processed file: D:\acltest\Trooper.txt
processed file: D:\acltest\web-core.jar
processed file: D:\acltest\Screens\adminGroup_perms.JPG
processed file: D:\acltest\Screens\admin_perms.JPG
processed file: D:\acltest\Screens\AdvSecuritySetting_AllowAdminGroup_perms
processed file: D:\acltest\Screens\AdvSecuritySetting_AllowAdminGroup_perms
processed file: D:\acltest\Screens\AdvSecuritySetting_AllowAdmin_perms_1.JPG
processed file: D:\acltest\Screens\AdvSecuritySetting_AllowAdmin_perms_2.JPG
processed file: D:\acltest\Screens\AdvSecuritySetting_AllowEveryone_perms_1.
processed file: D:\acltest\Screens\AdvSecuritySetting_AllowEveryone_perms_2.
processed file: D:\acltest\Screens\AdvSecuritySetting_DenyAdmin_perms.JPG
processed file: D:\acltest\Screens\AdvSecuritySetting_noInherit_perms.JPG
processed file: D:\acltest\Screens\EffectivePerm_Everyone_1.JPG
processed file: D:\acltest\Screens\EffectivePerm_Everyone_2.JPG
processed file: D:\acltest\Screens\EVERYONE_PERMS.JPG
processed file: D:\acltest\Screens\MappedFolder_Perms.JPG
Successfully processed 18 files; Failed processing 0 files

The /T switch allows it to get subfolder permissions too. The /C switch allows it to continue even if errors are encountered (although errors will still be displayed).

D:\>icacls D:\ /restore perms.txt
processed file: D:\acltest
processed file: D:\acltest\Screens
processed file: D:\acltest\Trooper.txt
processed file: D:\acltest\web-core.jar
processed file: D:\acltest\Screens\adminGroup_perms.JPG
processed file: D:\acltest\Screens\admin_perms.JPG
processed file: D:\acltest\Screens\AdvSecuritySetting_AllowAdminGroup_perms
processed file: D:\acltest\Screens\AdvSecuritySetting_AllowAdminGroup_perms
processed file: D:\acltest\Screens\AdvSecuritySetting_AllowAdmin_perms_1.JPG
processed file: D:\acltest\Screens\AdvSecuritySetting_AllowAdmin_perms_2.JPG
processed file: D:\acltest\Screens\AdvSecuritySetting_AllowEveryone_perms_1.
processed file: D:\acltest\Screens\AdvSecuritySetting_AllowEveryone_perms_2.
processed file: D:\acltest\Screens\AdvSecuritySetting_DenyAdmin_perms.JPG
processed file: D:\acltest\Screens\AdvSecuritySetting_noInherit_perms.JPG
processed file: D:\acltest\Screens\EffectivePerm_Everyone_1.JPG
processed file: D:\acltest\Screens\EffectivePerm_Everyone_2.JPG
processed file: D:\acltest\Screens\EVERYONE_PERMS.JPG
processed file: D:\acltest\Screens\MappedFolder_Perms.JPG
Successfully processed 18 files; Failed processing 0 files

NOTE: In the command to save the permissions, I specified the target folder D:\acltest, but when I restored them, I specified just D:\ as the target.

xampp mysql remote access

2012-07-02T23:40:00.000-07:00

To allow remote connections to mysql server on windows follow the steps below:

1) Login to mysql server through command line and execute the following query:

GRANT ALL PRIVILEGES ON *.* TO root@"%" IDENTIFIED BY 'password';

2) open the my.ini located inside the folder "C:\xampp\mysql\bin"
uncomment the line and replace 127.0.0.1 to

bind-address 0.0.0.0

VNC Server On Ubuntu

2012-06-12T05:48:00.005-07:00

#sudo apt-get install vnc4server

Now setup a password to login using the following command. It will prompt to setup a password and verify it

#vncpasswd

Than run the vnc server using

#vncserver :1

Now before you proceed kill it once using

#vncserver -kill :1

Now open the config file from .vnc/xstartup or ~/.vnc/xstartup

using editor .vnc/xstartup

Than uncomment the line which says

unset SESSION_MANAGER

And add sh to the line below it like this

exec sh /etc/X11/xinit/xinitrc

Exit the file and run the command as below

#vncserver :1 -depth 16 -geometry 1024×768

connect using <ip-addr>:1 (:1 is for the vnc server window)

You now have GUI access to your server.

Howto Build a MySQL Cluster in Debian Based Systems

2012-01-16T22:04:00.001-08:00

About the MySQL Cluster

Each MySQL Cluster host computer running an SQL node must have a MySQL binary installed. For management nodes and data nodes, it is not necessary to install the MySQL server binary, but management nodes require the management server daemon (ndb_mgmd) and data nodes require the data node daemon (ndbd). It is also a good idea to install the management client (ndb_mgm) on the management server host. This section covers the steps necessary to install the correct binaries for each type of Cluster node. This may be confusing but will make sense later.

In this example, we will use 5 Debian Lenny servers. You should start with a clean operating system installation for this tutorial. If you've already tried installing MySQL packages, you may have problems due to inconsistencies. All steps below should be performed as root.

The 5 servers to be used in this tutorial are as follows:

mysqlmanagement.example.com: 192.168.1.10 [ mysqlmanagement ]
mysqlnode1.example.com:  192.168.1.20 [ mysqlnode1 ]
mysqlnode2.example.com:  192.168.1.30 [ mysqlnode2 ]
mysqldatanode1.example.com:  192.168.1.40 [ datanode1 ]
mysqldatanode2.example.com:  192.168.1.50 [ datanode2 ]

MySQL Cluster 7.0 Management Server Installation [mysqlmanagement]

Visit http://dev.mysql.com/downloads/cluster and locate the Linux x86 and copy the url of the "Download". Your exact version may vary.

cd /var/tmp
wget http://dev.mysql.com/get/Downloads/MySQL-Cluster-7.0/mysql-cluster-...
tar -zxvf mysql-cluster-gpl-7.0.6-linux-i686-glibc23.tar.gz
cd mysql-cluster-gpl...
cp bin/ndb_mgm* /usr/local/bin

After copying the files, we can delete the gzip and extracted directories since we won't need them anymore.

rm -r /var/tmp mysql-cluster*

Change directories to the bin directory and adjust permissions on the nbd_mgm files

cd /usr/local/bin
chmod +x ndb_mgm*

Create a lib directory and create a config file for the cluster manager

mkdir /var/lib/mysql-cluster
cd /var/lib/mysql-cluster
nano config.ini

Add the following default options to the configuration file:

 
# Options affecting ndbd processes on all data nodes:
[ndbd default]
NoOfReplicas=2    # Number of replicas (This must match the number of data nodes!!!)
DataMemory=256M   # How much memory to allocate for data storage
IndexMemory=64M   # How much memory to allocate for index storage
                  # For DataMemory and IndexMemory, we have used the
                  # default values. Since the "world" database takes up
                  # only about 500KB, this should be more than enough for
                  # this example Cluster setup.
  
[tcp default]
#portnumber=2202  # This the default; however, you can use any port that is free
                  # for all the hosts in the cluster
                  # Note: It is recommended that you do not specify the port
                  # number at all and allow the default value to be used instead

# Management process options  
[ndb_mgmd]
hostname=192.168.1.10  # Hostname or IP address of management node
datadir=/var/lib/mysql-cluster  # Directory for management node log files
 
# First Data Node (ID=2 because the management node autmatically obtains ID=1) 
[ndbd]
Id=2
hostname=192.168.1.40
datadir=/usr/local/mysql/data

# Second Data Node
[ndbd]
Id=3
hostname=192.168.1.50
datadir=/usr/local/mysql/data

# MySQLD Processing Nodes (workhorses) - Defining 4 will allow 4 nodes to join the cluster
# from any location on the network. We use 4 because our data nodes also have
# mysqld running, so we are going to use them to process as well.
[mysqld]
[mysqld]
[mysqld]
[mysqld]

Start the Cluster Management Server by loading config.ini file for the first time

ndb_mgmd --initial -f /var/lib/mysql-cluster/config.ini

The cluster management server is now running. We will leave this server alone for now until we start joining data and sql nodes to the cluster.

MySQL 5.1 Installation [mysqlnode1 | mysqlnode2 | mysqldatanode1 | mysqldatanode2]

Visit http://dev.mysql.com/downloads/cluster/7.0.html and locate the Linux x86 copy the url of the "Download". Your exact version may vary. Complete the following steps on all 4 nodes (data and sql).

Add the user and group mysql

groupadd mysql
useradd -g mysql mysql
cd /var/tmp

Download the binary using wget and pasting the URL from above

wget http://dev.mysql.com/get/Downloads/MySQL-Cluster-7.0/mysql-cluster...

Unzip the package, then delete the tar.gz left behind

tar -C /usr/local -xzvf mysql-VERSION-OS.tar.gz
rm -f mysql-VERSION-OS.tar.gz

Rename the extracted folder to mysql. This is where the mysql binary is installed.

cd /usr/local
mv mysql-VERSION-OS mysql

Change directories and adjust permissions

cd mysql
chown -R mysql .
chgrp -R mysql .

Install mysql and adjust permissions after the install

scripts/mysql_install_db --user=mysql
chown -R root .
chown -R mysql data
chgrp -R mysql .

Copy the mysql startup file and adjust permissions

cp support-files/mysql.server /etc/init.d/mysql
chmod +x /etc/init.d/mysql

Set mysql to start on boot

cd /etc/init.d/
update-rc.d mysql defaults

Specify in your PATH the bin directory so we can execute mysql commands without the need to type the full path to mysql. Echo the current path then replace it with mysql added:

echo $PATH
export PATH="REPLACEWITHCOPIEDOUTPUTOFPATH:/usr/local/mysql/bin"

Create the my.cnf file (MySQL Configuration File

nano /etc/my.cnf

For all 4 MySQL nodes, my.cnf should look like this:

[mysqld]
ndbcluster
ndb-connectstring='host=192.168.1.10'    # IP address of the management server

[mysql_cluster]
ndb-connectstring='host=192.168.1.10'    # IP address of the management server

Create the mysql lib directory on all 4 nodes

mkdir /var/lib/mysql

Set the root password on the data nodes [ mysqldatanode1 | mysqldatanode2 ]

mysqladmin -u root password YOURSTRONGROOTPASSWORD

On [ mysqldatanode1 ], run this command to connect to the management server, which is already running from before. Note: Only use "--initial" if this is the first time you are connecting to the management server, or if the config.ini has changed on the management server.

cd /usr/local/mysql/bin
./ndbd --initial

On [ mysqldatanode2 ], run this command.

cd /usr/local/mysql/bin
./ndbd --initial

On [ mysqlnode1 ], run this command.

cd /usr/local/mysql/bin
./ndbd --initial

On [ mysqlnode2 ], run this command.

cd /usr/local/mysql/bin
./ndbd --initial

The output should look something like this on each node:

[ndbd] INFO -- Configuration fetched from '192.168.1.40:1186'

Test management server to see if cluster is running

On the management server, test to see if the cluster is running and the nodes have connected to the management server. It may take a few minutes to connect.

ndb_mgm
ndb_mgm> show;

Output should look like this:

Connected to Management Server at: localhost:1186
Cluster Configuration
---------------------
[ndbd(NDB)] 2 node(s)
id=3 @192.168.1.50  (mysql-5.1.34 ndb-7.0.6, Nodegroup: 0)
id=2 @192.168.1.40  (mysql-5.1.34 ndb-7.0.6, Nodegroup: 0, Master)

[ndb_mgmd(MGM)] 1 node(s)
id=1 @192.168.1.10  (mysql-5.1.34 ndb-7.0.6)

[mysqld(API)] 2 node(s)
id=4  @192.168.1.40  (mysql-5.1.34 ndb-7.0.6)
id=5  @192.168.1.50  (mysql-5.1.34 ndb-7.0.6)
id=6  @192.168.1.20  (mysql-5.1.34 ndb-7.0.6)
id=7  @192.168.1.30  (mysql-5.1.34 ndb-7.0.6)

If you see that everything is connected, then things are OK and you can start MySQL on all of your nodes.

Start MySQL on all 4 nodes

/etc/init.d/mysql start

If not, then repeat the steps and ensure you didn't miss anything.

quit;

Test enter some data into your cluster

On [ mysqldatanode1 ] create a table and enter some data

mysql -u root -p
CREATE DATABASE mysqlclustertest;
USE mysqlclustertest;
CREATE TABLE testtable (I INT) ENGINE=NDBCLUSTER;
INSERT INTO testtable () VALUES (1);
SELECT * FROM testtable;

On [ mysqldatanode2 ], see if the database was mirrored and the data

mysql -u root -p
USE mysqlclustertest;
CREATE TABLE testtable (I INT) ENGINE=NDBCLUSTER;
INSERT INTO testtable () VALUES (1);
SELECT * FROM testtable;

If you can use the database and retrieve the data, your replication was a success. If not, retrace all steps above and try again.

Further testing of data. On [ mysqldatanode2 ] create a table and enter some data

mysql -u root -p
USE mysqlclustertest;
INSERT INTO testtable () VALUES (2);
SELECT * FROM testtable;

Now go back to [ mysqldatanode1 ] and see if the value was replicated

mysql -u root -p
USE mysqlclustertest;
SELECT * FROM testtable;

Source: http://www.ctrip.ufl.edu/