Restore Data - Linux File System - Full System Restore

To recover OES file system data in the event of a disaster, perform a full system recovery of Linux file system to rebuild the operating system.

Before You Begin

The full system restore operation for a Linux system includes the following general steps. Detailed instructions are provided in the following section.

  1. Install a default install on the system that you want to restore.
  2. Install the Linux File System iDataAgent on the default install.
  3. Create and mount a root file system on the system that you want to restore.
  4. If any additional file systems were lost, create and mount them as well.
  5. Use the Linux File System iDataAgent to restore your data.

    • This recovery procedure is for basic systems without MetaDisks or Logical Volume Management software.
    • For this procedure, you must use a default installation of Linux.

Procedure

To perform a full system restore:

Try to avoid the unconditional overwrite of the root directory on a live file system. This is a mechanism that allows an unconditional overwrite of open files in the root directory (/) on a live file system. Performing such a restore can result in an inconsistent system that may also fail to boot. Use this option AT YOUR OWN RISK.

  1. When you perform a full system restore, the client computer must have a default install partition with the Linux File System iDataAgent installed on the default install. Do not install the default install on the same disk partition that will contain the restored root file system. Install the default install with the networking option enabled. The TCP/IP, hostname, and domain name settings of the default install must match those of the system that you are restoring.

    If you install the default install on an external drive, it can be used for other systems. However, you will have to remove and re-install the Linux File System iDataAgent software for each client. In addition, you will have to reconfigure TCP/IP, hostname, and domain name settings for each system.

  2. Load a default install (minimal install) Linux installation on a bootable partition of your system. Once the software is installed, boot that partition using a boot disk or LILO (Linux Loader).
  3. Install the Linux File System iDataAgent software. When the Linux File System iDataAgent is installed, continue with the next step.

    For more information, see Deployment - Linux File System iDataAgent.

    Use restored or saved data to obtain the information needed to repartition and label the new disk.

  4. Create partitions/slices on the disk by entering the following command:

    fdisk [-l] [-b SSZ] [-u] device

  5. Create the root file system by entering the following command:

    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.

  6. Mount the new root file system at /mnt by entering the following command:

    mount /dev/<hda1> /mnt

    where <hda1> is the Drive Identifier of the partition containing the root file system.

    If any other file systems existed on the root disk before the system crash, you must recreate them as well. For each file system, enter the following command:

    mkfs [-V] [-t fstype] [fs-options] /dev/<hda2> [size]

    where <hda2> is the Drive Identifier of the partition containing the file system that was lost.

  7. Create an empty directory called "proc" on /mnt as follows:

    mkdir /mnt/proc

  8. If you have recreated any file systems other than root, you must mount these as well. For each file system, enter the following commands:

    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.

  9. From the CommCell Console, right-click the backup set that contains the backup data of the root file system, click All Tasks, click Restore, type "/" as the path to restore from, type or accept "/mnt" as the restore destination, and use the Advanced tab to exclude from the content of the restore any file systems that were not affected by the system crash.

    Do not select Unconditional Overwrite from the Restore Options dialog box.

  10. When restoring encrypted data, refer to Data Encryption.
  11. Click OK to start the restore.
  12. Verify that the restore operation has completed successfully.
  13. If required, install either the LILO or grub boot loader (per the boot loader that was used in your environment) to the restored disk. Be sure to refer to the documentation for your distribution for the appropriate syntax and usage for your boot loader. For example, the following indicates use of the grub boot loader:

    chroot /mnt
    grub-install /dev/<hda>

  14. where <hda> is the Drive Identifier of the partition containing the root file system.
    Exit and reboot the computer. The system boots to the newly restored root.

The procedure is now complete.

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. Also, 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.