Markus Blog

Delete Files Older Than n Days

In Linux system you can delete old unused files (usually the session files in /tmp) all at once by running this command:

find /path/to/files* -mtime +5 -exec rm {} \;

this command will delete files which is 5 days old, if you want to change the number of days to 3 days old, then you have to change +5 to +3 and run the command again.

error: kernel image does not exist: /boot/hypervm-xen-vmlinuz

If you have a CentOS Xen Dom0 and experiencing this problem “error: kernel image does not exist: /boot/hypervm-xen-vmlinuz” after upgrading Xen kernel on HyperVM based VPS, here is how to fix it: More »

Changing Windows Server 2003 Administrator Password

It’s very easy to change Windows Server 2003 Administrator password if you have physical access to the server, you’ll need to press ctrl + alt + del and you’ll get some option buttons such as Lock Computer, Log Off, Shut Down, etc. on that window, click on Change Password to change your Administrator password (user that currently logged in, so you must log in as Administrator before you can change its password). More »

Xen VPS modprobe: QM_MODULES: Function not implemented

I got this problem on one of Debian VPS when tried to run iptables command

modprobe: QM_MODULES: Function not implemented
 
modprobe: QM_MODULES: Function not implemented
 
modprobe: Can't locate module ip_tables
iptables v1.3.6: can't initialize iptables table `filter': iptables
who? (do you need to insmod?)
Perhaps iptables or your kernel needs to be upgraded.

To fix this you’ll need to run these commands:
More »

Meaning of /dev/null 2>&1 in Crontab’s Cron Job

If you use cron job on Linux, some times you want to ignore the output of the command you executed. This can be done by adding “> /dev/null 2>&1” behind the cron job command.

The command is just work want it should be, but I always curious with what does 2>&1 means. The “> /dev/null” is pretty obvious of what it does without much more explanation, it just redirect all the output to /dev/null which in Linux means we don’t care with the output (or sort of, it’s my own definition). More »

Xen Debian VPS Problem With nash-hotplug Using 100% CPU Resource

Recently I setup a Debian 4.0 VPS using xen image from jailtime.org, once the VM running I noticed that the load goes 1.0 all the time which make the VM very slow. From top command you’ll see the nash-hotplug process is the cause.

First you can kill it by execute the ‘kill -9 <process id>’ command (without the quotes), where <process id> is the process id of nash-hotplug. Then to automate killing the nash process every time you reboot the VPS run these commands: More »

CPanel Problem Upgrading MySQL 5

Several months ago I had problem on upgrading CPanel’s MySQL 4.1 to MySQL 5. The problem was occurred on Centos 5 OpenVZ based VPS. Since someone contact me at WebHostingTalk forum asking about the same problem so I decided to re-try again the steps to fix the problem. Hence I post it here too, for future and general purposes

ok, do this at your own risk backup your mysql data first!

the steps i do:

More »

Xen VPS “4gb seg fix up” Problem

It’s a known issues on Xen based Virtual Private Server (VPS) that often it shows “4gb seg fix up” error messages. After a few search I found this command to fix it.

Run the commands below on DomU

First try disabling tls by renaming it to tls.disabled:

mv /lib/tls /lib/tls.disabled

If this doesn’t work then try this command:

echo 'hwcap 0 nosegneg' > /etc/ld.so.conf.d/libc6-xen.conf && ldconfig

after that you’ll need to restart the VPS