Creating a clone server in linux

[Ritesh Singh]

I have a server of REDHAT Linux 5 and I want another server to continue the working of clients whenever the main server gets failed to work. Whole work would be assigned to the second server and the main server will be recovered at that moment.So how could I do this.Please go through the steps to create the new server and what are tools would be necessary for this task .

Thanks for your Support.

[Calvin K]

If you are using the Linux Red Hat Linux and need to create a clone server to access when the main server would be failed to run.

Actually,you would not make so much changes but some physical things are necessary to have with you.The process includes exact as taking the backup of database.For each drive on the server,you have to make each clone disk.

The Image copy of the whole server is transferred to the clone disks that you have configured and you need to maintain the host name and IP Address of the server otherwise the clients got difficulties to access the clone server.

[Lillebror]

Creating a duplicate drive :

The Drives which is using with server,you are going to make the clone of that drives so you need to care about the users,privileges and all.

Calvin said earlier,You need to maintain the host name and IP address of the server to continue the work of end users.Now the dd command would be used to create the clone drive :

dd if=/dev/sda of=/dev/sdb
dd if=/dev/sda of=/backup_img/disk.img //Creating the image of the main server on its own disk

These statements are used to create the exact clone and it can take more time depends upon the size of the server.Divert the cloned drive into the target server and covert the host name and IP Address into different because both can not contact with each other.

[jesse]

If you get successful to create the clone disk and located to the proper disk then you need to do some files and directories configurations for synchronization

The rsync command would be executed with ssh to commit a reliable and secure connection with transportation of data. This is simplest method can be performed on small and Local network.

I am going to synchronize the /var Directory which would be as follows:

rsync -avhe ssh /var/ root@192.168.5.49:/var/

In this way,you have to synchronize the required directories like HOME and ETC would be as follows.

[SalVatore]

It is necessary to create an account on the server machine so that you don't worry to have a password needed to type after each update.

This task would be performed in the following manner :

Generate Key Pairs :

Key pairs are automatically created in the ~/.ssh home directory of particular user.The ~ symbol is used to locate the home directory of a user in linux.Now
Open a terminal and type: ssh-keygen -t dsa

1- Share Public Key
2- Copy Public Key