To change the SSH port number login as root, and edit /etc/ssh/sshd_config

Find the line that says Port 22 and change 22 to any number between 1024->65535 (above 30000 is best) and save the file.

Once done, run:

/etc/init.d/sshd restart

Now start a new SSH session (don’t close your existing one), to make sure that you can get in.

If rpm / yum command hangs during operations or you see error messages - it means your rpm database corrupted. /var/lib/rpm/ stores rpm database just delete the same and rebuild rpm database:

Command to rebuild rpm database

rm -f /var/lib/rpm/__db*
rpm --rebuilddb -v -v

Read rpm / yum man pages for more information

OK, so you are ready to move your server to a different datacenter with a different IP C class.

Here are a few things you need to change

For whatever reason CentOS decided to drop netconfig and renamed it to

system-config-network

How To Mount A Drive In Linux

Initially you wanna check the hard drives on your system

fdisk -l

so now you now whats being seen by the system
 

The mounting point path must already be created with proper permissions. So a more likely flow of commands would be below:

How To Unmount A Drive In Linux

This command is very easy to type wrong. It is NOT unmount. Take another closer look if thats what you saw at first. It is umount -- no n here!

For whatever reason , some people still want to run the old version of MySQL4.1 in there new cPanel servers, which seems a little issue , as the default database version in new cPanel server installs is MySQL5.

Here are the simple steps to downgrade the database (this should only be done on a new server without any account on it yet)

Need to know the exact size of your subdirectories in Linux?

Just go to the directory , like cd / and try this

du -cksh *

Had an issue with one on our CentOS cPanel servers running 64 bit and cPanels easyapache upgrade. The folks at cPanel helped out with their usual professional response

 Open SSH and type the following and press Enter:

/sbin/ifconfig | grep -i hwaddr

The sequence of hexadecimal digits that appears to the right of eth0 HWAddr (e.g. 08:00:27:ED:DA:8b) is your network card's MAC Address

Sometime accounts are to big to transfer via the WHM transfer feature.

Below you can find some steps to do so manually 

If you have issues with cPanel running CentOS5 with BIND then the easiest way is to downgrade BIND to 9.2.4

The reason you're having trouble is because CentOS 5 uses bind-9.3 and CentOS 4 uses bind-9.2 - The changes between these versions is significant enough that cPanel won't work with it properly.

For instance by default there is no /etc/named.conf file created when bind-9.3 is installed and the default named.conf file for bind-9.3 is significantly different than in older versions.

Until the code is updated to work with bind-9.3, I have found the workaround to be to remove bind-9.3 packages and install bind-9.2 packages as follows:
 

check what kernel you are running at the moment

uname -a

and to upgrade your kernel

yum update \kernel*

check if your kernel is added to grub

cat /boot/grub/grub.conf

and then reboot

shutdown -rf now

Log into SSH

mkdir $HOME/.ssh
chmod -R og= $HOME/.ssh
cd .ssh
nano authorized_keys2

Add your key you created with PuttyGen , make absolutly sure you r key is in one line ONLY , otherwise it wont work!

Adjust your  sshd_config

nano /etc/ssh/sshd_config

to

RSAAuthentication yes
PubkeyAuthentication yes
AuthorizedKeysFile      .ssh/authorized_keys2