January 16th, 2015
Do you have openvz or virtuozzo container and often you see this error message when trying to su to root?
# su –
su: cannot set user id: Resource temporarily unavailable
Solution is simple, you need to increase limits in /etc/security/limits.conf
These values work fine
* soft nproc 2047
* hard nproc 16384
* soft nofile 1024
* hard nofile 65536
September 29th, 2013
long time no update. I’ve been busy, but now I’m back and ready to publish few more helpful articles. Today it is about annoying Putty window re-size when you during active ssh session to CentOS 6 server enter ‘screen’. It gets resized and disturbs your mindful thoughts At least it does that to me and I hate it.
The solution is to edit /etc/screenrc and add this line:
termcapinfo xterm* 'is=\E[r\E[m\E[2J\E[H\E[?7h\E[?1;4;6l'
This fixes it and it will no longer resize putty window. Enjoy !
April 6th, 2012
Maybe you also had experienced the situation where you could not log in into cPanel after the recent upgrade to 11.32.15 version. I had the same problem but fixed it with help of cPanel support staff. Here is what the error is and how to solve it..
Read the rest of this entry »
March 28th, 2012
Today I could not update my perl packages on 64bit Centos because they were conflicting with 32bit version of perl packages
I’m sure you’ve experienced it some day, the error message looks like this:
Transaction Check Error:
file /usr/lib/perl5/5.8.8/CGI.pm from install of perl-5.8.8-32.el5_7.6.x86_64 conflicts with file from package perl-5.8.8-32.el5_6.3.i386
After some investigation I found out that the problem lies in installed 32bit version but distribution want to update 64bit version. Some packages in yum update are asking for the 64bit version and that results in such conflict.
The solution is very simple – just delete 32bit perl and install perl 64bit from scratch using these commands:
yum remove perl.i386
yum install perl
March 5th, 2012
Few days ago I was surprised that many error messages started to flood my logs on couple of Cpanel/WHM server where I use php 5.2.17. The error was the following:
[05-Mar-2012 18:18:59] PHP Warning: PHP Startup: Suhosin Extension
does not officially support PHP 5.2 and below anymore, because it is
discontinued. Use it at your own risk. in Unknown on line 0
However, bad situation but I have a fix..
March 5th, 2012
Virtual servers are good and very popular during recent years. However, their main bottleneck is IO operations. Slow hdd storage can ruin your vps even when you have enouch RAM and CPU power. I myself have few vpses around the world and show you what I measured so far and how to measure it using ioping.
January 13th, 2012
Have you ever had problem updating perl via yum and yum spitting a conflict error message at you? I’ve met this problem on few CentOS 5 boxes of mine and thought I share the solution.
I happens on 64bit boxes and the error is for example like this
file /usr/share/man/man1/splain.1.gz from install of perl-5.8.8-32.el5_7.6.x86_64 conflicts with file from package perl-5.8.8-32.el5_6.3.i386
file /usr/share/man/man1/xsubpp.1.gz from install of perl-5.8.8-32.el5_7.6.x86_64 conflicts with file from package perl-5.8.8-32.el5_6.3.i386
file /usr/share/man/man3/CGI.3pm.gz from install of perl-5.8.8-32.el5_7.6.x86_64 conflicts with file from package perl-5.8.8-32.el5_6.3.i386
Obviously it is a problem of having a i386 version along the 64bit. First you need to remove the i386 version and then install perl again. You can do it by executing this command:
yum -y remove perl.i386 && yum -y install perl
It should work and you end up with a correct installation of perl. Until the next update 😉
November 11th, 2011
Recently I have fallen for Battlefield 3 and this game forced me to buy a new gaming mouse. Early x-mas 😉 I decided to buy Roccat Kone+ and was surprised this mouse has upgradable firmware. The one I purchased had old fw so I decided to upgrade it.. However, it did not work and I did many attempts, turned on/off antivirus, and all other software that could block the upgrade process. Then I was advised to try older version of drivers and then try the latest one and this procedure worked… therefore I bring you step by step instructions how to upgrade driver and firmware on your Roccat Kone+ mouse..
Only in case the regular procedure with latest drivers ( 1.49/1.45 ) doesn’t work, please go ahead with the following workaround!
1.) Uninstall the driver completely
2.) Install the driver “1.45/1.40″
<<<In case the firmware update should not start automatically, do the following steps (otherwise skip step 3+4 and go ahead with 5!)>>>
3.) Go to your C:\Programs\ROCCAT\Kone[+] Mouse\FWupdate
4.) Execute the Kone[+] Firmware Updater.exe
5.) Now uninstall the driver 1.45/1.40 again.
6.) Finally install the most recent driver 1.49/1.45
This worked for me and it is the official procedure that Roccat advises. Feel free to leave comments if this worked for you too! Enjoy gaming with this great mouse.
June 6th, 2011
If you are on cpanel (or any other centos server) and need the security feature that root cannot log in via ssh (I will cover this elsewhere) you can do it by adding new user by using these commands:
# adduser testuser
# passwd testuser
that will create the user “testuser” and prompts you to enter his password
With this you would not be able to su to root, therefore you need to add this user to wheel group by using command:
# usermod -f wheel testuser
Voila, now user “testuser” will be able to su – to root and you can disable direct root login in your ssh configuration.
November 21st, 2010
Do you use your spare server power to compute BOINC projects? Seti@Home or MilkyWay or some others ?
You surely encountered error on CentOS 5 or RHEL 5 these errors:
./boincmgr: error while loading shared libraries: libXcomposite.so.1: cannot open shared object file: No such file or directory
./boincmgr: error while loading shared libraries: libXdamage.so.1: cannot open shared object file: No such file or directory
The cure is actually pretty easy, you just need to install the missing libraries
yum install libXcomposite libXdamage
And your problem should be vanished.. Also, you may need these libraries, but those should be installed by default: zlib, openssl, curl-devel
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