SysAdmin.be

Mac OS X: how to generate md5 sha1 sha256 checksums from command line

noreply@blogger.com (DJ) — Sat, 06 Dec 2014 16:18:00 +0000

Calculate MD5 checksum:
md5 /tmp/1.iso
Calculate SHA-1 checksum:
shasum -a 1 /tmp/1.iso
Calculate SHA-256 checksum:
shasum -a 256 /tmp/1.iso

how to set your timezone

noreply@blogger.com (DJ) — Sun, 07 Sep 2014 13:35:00 +0000

[root@vps zoneinfo]# cp /usr/share/zoneinfo/CET /etc/localtime

You need to adjust "/usr/share/zoneinfo/CET" and adapt it to your local timezone.

bash: warning: setlocale: LC_CTYPE: cannot change locale (UTF-8): No such file or directory

noreply@blogger.com (DJ) — Sun, 07 Sep 2014 13:28:00 +0000

Macintosh-3:~ user$ ssh root@vps.server.com
root@vps.server.com's password:
Last login: Sun Sep 7 17:07:46 2014 from x.x.x.x
-bash: warning: setlocale: LC_CTYPE: cannot change locale (UTF-8): No such file or directory
[root@vps ~]# locale
locale: Cannot set LC_CTYPE to default locale: No such file or directory
locale: Cannot set LC_ALL to default locale: No such file or directory
LANG=en_US.utf8
LC_CTYPE=UTF-8
LC_NUMERIC="en_US.utf8"
LC_TIME="en_US.utf8"
LC_COLLATE="en_US.utf8"
LC_MONETARY="en_US.utf8"
LC_MESSAGES="en_US.utf8"
LC_PAPER="en_US.utf8"
LC_NAME="en_US.utf8"
LC_ADDRESS="en_US.utf8"
LC_TELEPHONE="en_US.utf8"
LC_MEASUREMENT="en_US.utf8"
LC_IDENTIFICATION="en_US.utf8"
LC_ALL=
[root@vps ~]# vi /etc/sysconfig/i18n

LANG="en_US.utf8"
LC_CTYPE="en_US.utf8"
LC_ALL="en_US.utf8"

[root@vps ~]# source /etc/sysconfig/i18n

problem solved :)

Change TimeZone on AIX

noreply@blogger.com (DJ) — Mon, 03 Jun 2013 09:00:00 +0000

Use
smitty chtz_date

Note that a reboot is required to activate changes.

How to reproduce ORA-04031

noreply@blogger.com (DJ) — Thu, 28 Feb 2013 12:39:00 +0000

You are able to reproduce the ORA-04031 with shared pool depletion by pin dbms_shared_pool procedure by all the cursor on the SGA as shown below, it prohibits the release.

 conn / as sysdba
 declare
   i number;
   j char (30);
   sqlstr varchar2 (100);
   cursor cur_pin is
    select rawtohex (address) | | ',' | | to_char (hash_value)
    from sys.v_ $ sql where kept_versions = 0;
   rec_pin varchar2 (1000);
 begin
   i: = 1;
   loop
     loop
       i: = i +1;
       exit when i mod 1000 = 0;
       sqlstr: = 'select''' | | i | |'' 'from dual';
       execute immediate sqlstr into j;
     end loop;
     open cur_pin;
     loop
       fetch cur_pin into rec_pin;
       exit when cur_pin% notfound;
       dbms_shared_pool.keep (rec_pin, 'x');
     end loop;
     close cur_pin;
   end loop;
 end;
 /

Source: http://www.doppo1.net/oracle/trouble/ORA-04031.html

No buffer space available (maximum connections reached?)

noreply@blogger.com (DJ) — Mon, 25 Feb 2013 14:08:00 +0000

Caused by: java.net.SocketException: No buffer space available (maximum connections reached?): connect

This is most likely due to the number of ephemeral TCP ports being exhausted, the server has too many active client connections due to which the ephemeral TCP ports are all used up and in this case no more ports can be allocated to a new client connection request resulting in the behaviour we see here that no new connections can be setup.

Quoting from Wikipedia entry:
http://en.wikipedia.org/wiki/Ephemeral_port

"Ephemeral port is a transport protocol port for Internet Protocol (IP) communications allocated automatically from a predefined range by the TCP/IP Stack Software. It is typically used by the TCP, UDP or SCTP as port for the client end of a client-server communication when the application doesn't bind the socket to a specific port number, or by a server application to free up service's well known listening port and establish a service connection to the client host. The allocations are temporary and only valid for the duration of the connection. After completion of the communication session the ports become available for reuse, although most implementations simply increment the last used port number until the ephemeral port range is exhausted."

This is a known issue on Windows boxes, a hotfix is available from Microsoft: "Kernel sockets leak on a multiprocessor computer that is running Windows Server 2008 R2 or Windows 7" - http://support.microsoft.com/kb/2577795

http://rwatsh.blogspot.be/2012/04/resolution-for-no-buffer-space.html
http://dbaktiar-on-java.blogspot.be/2010/03/hudson-shows-buffer-space-available.html

HOW TO: Disable DNS caching

noreply@blogger.com (DJ) — Wed, 06 Feb 2013 16:14:00 +0000

For Solaris:
To disable the DNS cache on Solaris
1. Edit the file /etc/nscd.conf as follows:
a. un-comment the line # enable-cache hosts no.
b. add the line enable-cache ipnodes no after the line above.
2. To activate the changes, restart the nscd daemon by typing the command:
$ svcadm restart svc:/system/name-service-cache

For AIX:
To disable the DNS cache on AIX 6.1
DNS caching is managed by the network caching daemon (netcd).
1. stop the network caching daemon : #stopsrc -s netcd
2. prevent the network caching daemon from starting at boot time, edit the file /etc/rc.tcpip:
a. comment the line for the netcd daemon as follows:
# Start up binld daemon
#start /usr/sbin/binld "$src_running"
For more information see IBM Technote T1010925

For Linux:
To disable the DNS cache on Linux
1. Edit the file /etc/nscd.conf as follows:
a. un-comment or update the line to reflect: enable-cache hosts no
2. To activate the changes, restart the nscd daemon by typing the command:
# service nscd restart
3. Make sure the dnsmasq service not running:
a. stop the service : # service dnsmasq stop
b. disable the service from starting at boot time :
# chkconfig dnsmasq off
# chkconfig --list dnsmasq
dnsmasq 0:off 1:off 2:off 3:off 4:off 5:off 6:off
#

Use your arrow keys in AIX KSH

noreply@blogger.com (DJ) — Mon, 28 Jan 2013 14:07:00 +0000

login as root
open /root/.kshrc (change /root in caes you change the home dir of root)
add the following

set -o emacs
alias __A=`echo "\020"`     # up arrow = ^p = back a command
alias __B=`echo "\016"`     # down arrow = ^n = down a command
alias __C=`echo "\006"`     # right arrow = ^f = forward a character
alias __D=`echo "\002"`     # left arrow = ^b = back a character
alias __H=`echo "\001"`     # home = ^a = start of line
alias __Y=`echo "\005"`     # end = ^e = end of line

save the file
logout
login and you can make use of the arrow keys

Mount SMB Network Drive permanently

noreply@blogger.com (DJ) — Sun, 27 Jan 2013 20:05:00 +0000

How to mount a smb network drive permanently in Mac OS X:

1. Mount drive in Finder
2. Go to System Preferences > System > Users & Groups > your account > Login items tab
3. Add the SMB drive in the list of objects as if it was an application

Allow Excel 2010 to open separate windows.

noreply@blogger.com (DJ) — Mon, 03 Dec 2012 14:13:00 +0000

"
There is no real trick to getting Excel 2010 to open two screens side by side. There’s many tricks out there but none seem to work properly, if at all. Registry hacks can work but then other problems can arise and you need to fix those issues. Then you get in deep over your head and need to call a technician. Embarrassed to say what you did, the technician maybe racking up the hours trying to fix the registry because you probably didn’t back it up first.
It’s simple, have a shortcut to Excel on your desktop. Not a shortcut to the individual files, but a shortcut to the main Excel 2010 program. Open Excel, click File and open your file. Next, minimize that Excel document or move it to your other screen, out of the way so you can see the shortcut to Excel 2010. Open the second instance of Excel 2010 via the shortcut on your desktop. The second window comes up blank and available for you to go to File and open your second spreadsheet file.
Now you have two windows/instances of Excel 2010 at the same time which you can either overlap, side by side on same screen, or if you have two monitors, you can have one on each monitor.
"
Source: http://blog.twinbytes.ca/2012/10/25/excel-2010-open-separate-windows/

Windows XP SP3 wsus client not updating

noreply@blogger.com (DJ) — Fri, 19 Oct 2012 11:01:00 +0000

When you run the WSUS Client Diagnostics Tool, you get the following error at the end :

WinHttpDownloadFileToMemory(szURLDest, NULL, 0, NULL, NULL, NULL, &downloadBuffe r) failed with hr=0x80072efd

A connection with the server could not be established

In addition, your WSUS server is most likely not configured to listen on port 80.

In my case manually updating the WUAgent to v7.4 (x86 | x64) solved the problem.

I suspect the client is trying to execute a selfupdate but this fails because the WSUS server is not responding on port 80.

Invalid XSL format (or) file name.

noreply@blogger.com (DJ) — Wed, 26 Sep 2012 15:13:00 +0000

Are you executing some wmic commands, most likely with a format command and getting the following error : Invalid XSL format (or) file name.

for example : wmic process list FULL /FORMAT:CSV

You running on Windows 7 (64-bit) or Windows 2008 R2 and have installed additional keyboards or language settings.

It seems that some wmic commands use files that are located in a localized folder:

on 32-bit : C:\Windows\System32\wbem\en-US
on 64-bit : C:\Windows\SysWOW64\wbem\en-US

If you have for example a UK keyboard layout installed, simply copy C:\Windows\SysWOW64\wbem\en-US to C:\Windows\SysWOW64\wbem\en-GB.

Your format command above should work fine now.

HOWTO change the LS colors on RedHat/CentOS

noreply@blogger.com (DJ) — Fri, 23 Mar 2012 13:46:00 +0000

copy the /etc/DIR_COLORS file to your $HOME dir and make the necessary changes in the file.

Korn Shell

noreply@blogger.com (DJ) — Fri, 23 Mar 2012 13:18:00 +0000

enable TAB completion : set -o viraw (or use set -o vi, works on my redhat enterprise 5.7)

prompt formatting : PS1='[$USER@$HOSTNAME]:${PWD#${PWD%/*/*}/} # '

http://osr507doc.sco.com/en/OSUserG/_The_Korn_shell_profile_and_kshrc.html

SQL Server 2008 R2 - How to gain access to a new installation

noreply@blogger.com (DJ) — Tue, 29 Nov 2011 14:21:00 +0000

In case you ever need to connect to a fresh installation of MS SQL Server 2008 R2 and you were not added during the installation, follow this procedure to gain access :

http://beyondrelational.com/blogs/chintak/archive/2010/07/20/sql-2008-r2-new-installation-and-login-password-unknown.aspx

Disable UAC for Windows Servers through Group Policy

noreply@blogger.com (DJ) — Mon, 21 Nov 2011 13:23:00 +0000

In Computer Configuration | Policies | Windows Settings | Security Settings | Local Policies | Security Options configure the following values:

- User Account Control: Behavior of the elevation prompt for administrators in Admin Approval Mode
- User Account Control: Detect application installations and prompt for elevation
- User Account Control: Turn on Admin Approval Mode

Source.

Install XBMC on an Apple TV 2

noreply@blogger.com (DJ) — Sat, 19 Nov 2011 15:50:00 +0000

Link collection of what i used to install XBMC on my brand new apple TV 2 :

http://forum.xbmc.org/showthread.php?t=99315
http://support.firecore.com/entries/387605
http://wiki.xbmc.org/index.php?title=Install_XBMC_on_ATV2
http://wiki.xbmc.org/index.php?title=Install_XBMC_on_ATV2#Nightly
http://wiki.xbmc.org/index.php?title=XBMC_for_iOS_specific_FAQ#direct_boot

Pagefile Management for Windows Server Core

noreply@blogger.com (DJ) — Fri, 18 Nov 2011 16:40:00 +0000

First you need to disable the automatic management:

wmic
>computersystem where name="hostname" set AutomaticManagedPagefile=False

Next, you select where to put the pagefile and how big it should be (expressed in MB)

wmic
>pagefileset where name=”C:\\pagefile.sys” set InitialSize=8192,MaximumSize=8192

More info : http://blogs.dirteam.com/blogs/sanderberkouwer/archive/2007/12/27/page-files-in-server-core.aspx

Free eBook: TCP/IP Fundamentals for Microsoft Windows

noreply@blogger.com (DJ) — Fri, 18 Nov 2011 08:02:00 +0000

This online book describes the fundamentals of TCP/IP in Windows Vista, Windows Server 2008, Windows XP, and Windows Server 2003.

http://blogs.technet.com/b/johnbaker/archive/2011/11/10/free-ebook-tcp-ip-fundamentals-for-microsoft-windows.aspx

Free eBook: Understanding Microsoft Virtualization R2 Solutions

noreply@blogger.com (DJ) — Fri, 18 Nov 2011 07:52:00 +0000

Learn about the latest Microsoft Virtualization technologies, including Hyper-V and Windows Azure. Download Understanding Microsoft Virtualization R2 Solutions, written by industry expert Mitch Tulloch along with the Microsoft Virtualization team.

http://blogs.technet.com/b/johnbaker/archive/2011/11/04/free-ebook-understanding-microsoft-virtualization-r2-solutions.aspx

Securing an Ubuntu Server

noreply@blogger.com (DJ) — Wed, 02 Nov 2011 16:39:00 +0000

Action for me, still to do on my vps : http://www.andrewault.net/2010/05/17/securing-an-ubuntu-server/

Find empty directories

noreply@blogger.com (DJ) — Mon, 31 Oct 2011 12:49:00 +0000

Simple find command to find empty directories on a UNIX box :

find /path-to-directory -type d -empty

Back

noreply@blogger.com (DJ) — Wed, 26 Oct 2011 11:48:00 +0000

After a fairly long time being offline, i'll try to catch up again. Wish me luck!

Vacation

noreply@blogger.com (DJ) — Thu, 26 Nov 2009 21:14:00 +0000

Again my apologies for not updating, way to busy in real life. Leaving for a 2 week holiday now, so i should restart again mid december. Take care!

Attending Tech-Ed Europe 09

noreply@blogger.com (DJ) — Sun, 08 Nov 2009 10:01:00 +0000

I am leaving for Tech-Ed 2009, hosted in Berlin this year. I might post some updates here, will all depend if i find the time :-)