How to clone CentOS server to another one

 

Step 1: Installing the Rsync Tool in CentOS

For cloning to be successful the rsync command-line tool needs to be present on both servers. This will be used for mirroring the source server to the destination server and syncing all the differences between the two systems. Thankfully, modern systems come with rsync already pre-installed.

To check the version of rsync installed run:

$ rsync --version

If you want to view additional information about rsync, execute the following rpm command:

$ rpm -qi rsync

Check Rsync Version in CentOS

If rsync is missing, run the following command to install it in RHEL / CentOS / Fedora systems.

$ sudo yum install rsync

Step 2: Configure the Source Server

There are directories and files that you may want to exclude from cloning because they are either already available in the destination server or are autogenerated. These include the /boot, /tmp and /dev directories.

Therefore, create an exclusion file /root/exclude-files.txt and add the following entries:

/boot
/dev
/tmp
/sys
/proc
/backup
/etc/fstab
/etc/mtab
/etc/mdadm.conf
/etc/sysconfig/network*

Save and exit the configuration file.

Step 3: Clone the CentOS Server

With everything set, proceed and rsync your server to the remote or destination server using the command:

$ sudo rsync -vPa -e 'ssh -o StrictHostKeyChecking=no' --exclude-from=/root/exclude-files.txt / REMOTE-IP:/

Clone CentOS Server

The command will rsync everything from the source server to the destination server while excluding the files and directories you defined earlier on. Be sure to replace the REMOTE-IP: option with your destination server’s IP address.

After the syncing is done, reboot the destination system to reload the changes and thereafter, boot into the server using the source server’s credentials. Feel free to decommission the old server since you now have a mirror copy of it.

 

found at: https://www.tecmint.com/clone-centos-server/