EZ Linux Admin » Linux Commands

Clear bash history through ssh command line

EZ linux — Sun, 30 May 2010 20:01:12 +0000

history -c

Path to date

EZ linux — Tue, 25 May 2010 03:22:09 +0000

The server path to date can very for different servers, you will need to run this command to find it:

which date

For most servers it is:

/bin/date

This is the same for perl and php

setroubleshoot bug

EZ linux — Mon, 24 May 2010 06:20:07 +0000

There is a bug with the new option in Centos 5 called setroubleshoot.

The bug spins the program over and over causing high memory and sometimes CPU use. Unfortunately there is no permanent fix yet, but if you see something like this high in your daily process log:

/usr/bin/python -E /usr/sbin/setroubleshootd

To fix for now you simply have to restart the process:

/etc/init.d/setroubleshoot restart

When asking about a networking issue, get these details from the server

EZ linux — Mon, 05 Apr 2010 20:14:04 +0000

Kernal version

uname -a

Nic / Lan driver version

dmesg | grep r8169

Internet controller

lspci -nn | grep Ethernet

Details on etho nic card

sudo ethtool eth0

Module size

lsmod | grep r8169

Module versions

cat /proc/modules | grep r8169

Don’t worry all these commands are safe and just for reporting.

How to do a search and replace over multiple files

EZ linux — Fri, 19 Mar 2010 03:51:46 +0000

You could also use find and sed, but I find that this little line of perl works nicely.
perl -pi -w -e ’s/search/replace/g;’ *.php

-e means execute the following line of code.
-i means edit in-place
-w write warnings
-p loop

Example I had the following style sheet in a section:

and I wanted the following instead:

As each expression is a regular expression you’ve got to escape the special characters such as forward slash and .
\.\.\/includes\/style\.css

So the final line of code ends up as
perl -pi -w -e ’s/\.\.\/includes\/style\.css/admin\.css/g;’ *.php

Getting a md5sum error when tranferring a cpanel account?

EZ linux — Wed, 03 Mar 2010 12:19:41 +0000

This usually means you need to upgrade Perl on the server. Here is a example of a md5sum error.

The remote server didn’t report a correct md5sum of the archive. Please ensure you selected the correct type of remote server.

To fix upgrade Perl as shown here:

http://www.ezlinuxadmin.com/2009/08/upgrading-perl-on-cpanel/

My new favorite rsync command

EZ linux — Wed, 03 Mar 2010 12:04:33 +0000

rsync -vae ssh 12.123.123.123:/home/dwhsbackup/daily/username/ /backup/cpbackup/daily2/username/ –bwlimit=10000 –exclude-from ‘/root/exclude.txt’

Calm down rsync if it overloads your IO memory or CPU

EZ linux — Wed, 03 Mar 2010 11:57:14 +0000

The trick is to limit I/O bandwidth for rsync.

The –bwlimit option limit I/O bandwidth. You need to set bandwidth using KBytes per second. For example, limit I/O bandwidth to 10000KB/s (9.7MB/s), enter:

rsync –delete –numeric-ids –relative –delete-excluded –bwlimit=10000 /path/to/source /path/to/dest/?

10 megs a second is plenty of speed and will keep the server running smoothly when your grabbing allot of files off of it.

rsync running slow?

EZ linux — Wed, 03 Mar 2010 05:31:19 +0000

Today I was transferring files through rsync it was taking forever, my guess was the new server or old server was out of memory so I killed some procs and even rebooting the server but still it was crawling. So I thought I would think out of the box and after a couple trial and errors I tried a nic reboot and wow it was super fast from there.

/etc/init.d/network restart

I’m still not sure how the nic got blogged up but this worked like charm.

Keep in mind this is a temp fix, what you need to do is both your nic card going by adding another IP via cpanel and via the setup tool access from the root of the server. Try to separate the IP traffic that best that you can between both nic cards on the server.

Free /usr partition space by a symlink to domlogs

EZ linux — Thu, 11 Feb 2010 00:04:15 +0000

First move the domlogs folder to the backup partition:

mv /usr/local/apache/domlogs /backup

Then create a symbolic link to it:

ln -s /backup/domlogs /usr/local/apache/domlogs