Disaster Recovery - Linux File System

Planning for a Disaster Recovery

Before you begin a disaster recovery, make sure to do the following:

Perform regular backups of the Linux file system. These backups can be scheduled to run at convenient intervals.
Ensure that the destination client is same as source client while performing a disaster recovery.
Make sure to Install the Linux Operating System on the system that you want to restore. Make sure to install the Operating System exactly as it existed prior to a hardware or software corruption problem.
The client computer must have a default install partition with the Linux File System iDataAgent installed on it. Make sure to enable the Networking option. The TCP/IP, hostname, and domain name settings of the default install must match those of the system that you are restoring.
Create and mount a root file system on the system that you want to restore.

Rebuilding the Operating System

1.	Type the command to create partitions/slices on the disk.	fdisk [-1] [-b SSZ] [-u] device
2.	Type the command to create the root file system. mkfs [-V] [-t fstype] [fs-options] /dev/<hda1> [size] where <hda1> is the Drive Identifier of the partition where you want to create the root file system.	For example: mkfs [-V] [-t linux] [devfs] /dev/<hda1> [100]
3.	Type the command to mount the new root file system at /mnt. mount /dev/<hda1> /mnt Where <hda1> is the Drive Identifier of the partition containing the root file system.	For example: mount /dev/<hda1> /mnt
4.	If any other file systems existed on the root disk before the crash, type the command to recreate them as well.	mkfs [-V] [-t fstype] [fs-options] /dev/<hda2> [size]
5.	Create an empty directory called "proc" on /mnt	mkdir /mnt/proc
6.	If you have recreated any file systems other than root, type the command to mount these as well. mkdir /mnt/<file_system_name> mount /dev/<hda2> /mnt/<file_system_name> where <file_system_name> is the name of the file system and <hda2> is the Drive Identifier of the partition containing the file system.
7.	If required, install either the lilo or grub bootloader (per the bootloader that was used in your environment) to the restored disk.	For example: chroot /mnt grub-install /dev/<hda>
8.	Exit and restart the computer.

Restoring the Linux File System

From the CommCell Browser, navigate to Client Computers | <Client> | File System.
Right-click the defaultBackupSet and then click All Tasks | Restore.

Enter the Linux file system path to the data you wish to restore. You can type "/" as the path to restore the entire content.

Select the name of the client computer from the Destination Client list. If you are mounting the new root file system at /mnt, type or accept "/mnt" as the restore destination. Do not select Restore to same folder checkbox.

Click OK.

Do not select Unconditional Overwrite from the Advanced Options.

Restored data retains its original permissions. The ACLs are restored after the permissions are restored.

Select Immediate from the Job Initiation tab.
Click OK.

You can monitor the progress of the restore job in the Job Controller or Event Viewer window of the CommCell Console.

Exit and reboot the computer.

If you have installed to a new server where the mount points may be different, be sure to edit the fstab and mtab files in the restored /etc directory to match the new server. Also, be sure to edit the /boot/grub/menu.lst file to match the new configuration. If there are hardware changes, be sure to reboot to single user first so that you can add new drivers to the operating system if needed.

Disaster Recovery - Linux File System

Table of Contents

Planning for a Disaster Recovery

Rebuilding the Operating System

Restoring the Linux File System