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Chapter 9. Recovering and restoring a system

To recover and restore a system using an existing backup, Red Hat Enterprise Linux provides the Relax-and-Recover (ReaR) utility.

You can use the utility as a disaster recovery solution and also for system migration.

The utility enables you to perform the following tasks:

  • Produce a bootable image and restore the system from an existing backup, using the image.
  • Replicate the original storage layout.
  • Restore user and system files.
  • Restore the system to a different hardware.

Additionally, for disaster recovery, you can also integrate certain backup software with ReaR.

Setting up ReaR involves the following high-level steps:

  1. Install ReaR.
  2. Create rescue system.
  3. Modify ReaR configuration file, to add backup method details.
  4. Generate backup files.

9.1. Setting up ReaR

Use the following steps to install the packages for using the Relax-and-Recover (ReaR) utility, create a rescue system, configure and generate a backup.

Prerequisites

  • Necessary configurations as per the backup restore plan are ready.

    Note that you can use the NETFS backup method, a fully-integrated and built-in method with ReaR.

Procedure

  1. Install ReaR, the genisomage pre-mastering program, and the syslinux package providing a suite of boot loaders:

    # yum install rear genisoimage syslinux
  2. Create a rescue system:

    # rear mkrescue
  3. Modify the ReaR configuration file in an editor of your choice, for example:

    # vi /etc/rear/local.conf
  4. Add the backup setting details to /etc/rear/local.conf. For example, in the case of the NETFS backup method, add the following lines:

    BACKUP=NETFS
    BACKUP_URL=backup.location

    Replace backup.location by the URL of your backup location.

  5. To configure ReaR to keep the previous backup archives when the new ones are created, also add the following line to the configuration file:

    NETFS_KEEP_OLD_BACKUP_COPY=y
  6. To make the backups incremental, meaning that only the changed files are backed up on each run, add the following line:

    BACKUP_TYPE=incremental
  7. Take a backup as per the restore plan.