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Chapter 24. Restoring an XFS file system from backup

As a system administrator, you can use the xfsrestore utility to restore XFS backup created with the xfsdump utility and stored in a file or on a tape.

24.1. Features of restoring XFS from backup

The xfsrestore utility restores file systems from backups produced by xfsdump. The xfsrestore utility has two modes:

  • The simple mode enables users to restore an entire file system from a level 0 dump. This is the default mode.
  • The cumulative mode enables file system restoration from an incremental backup: that is, level 1 to level 9.

A unique session ID or session label identifies each backup. Restoring a backup from a tape containing multiple backups requires its corresponding session ID or label.

To extract, add, or delete specific files from a backup, enter the xfsrestore interactive mode. The interactive mode provides a set of commands to manipulate the backup files.

Additional resources

  • xfsrestore(8) man page.

24.2. Restoring an XFS file system from backup with xfsrestore

This procedure describes how to restore the content of an XFS file system from a file or tape backup.

Prerequisites

Procedure

  • The command to restore the backup varies depending on whether you are restoring from a full backup or an incremental one, or are restoring multiple backups from a single tape device:

    # xfsrestore [-r] [-S session-id] [-L session-label] [-i]
                 -f backup-location restoration-path
    • Replace backup-location with the location of the backup. This can be a regular file, a tape drive, or a remote tape device. For example, /backup-files/Data.xfsdump for a file or /dev/st0 for a tape drive.
    • Replace restoration-path with the path to the directory where you want to restore the file system. For example, /mnt/data/.
    • To restore a file system from an incremental (level 1 to level 9) backup, add the -r option.
    • To restore a backup from a tape device that contains multiple backups, specify the backup using the -S or -L options.

      The -S option lets you choose a backup by its session ID, while the -L option lets you choose by the session label. To obtain the session ID and session labels, use the xfsrestore -I command.

      Replace session-id with the session ID of the backup. For example, b74a3586-e52e-4a4a-8775-c3334fa8ea2c. Replace session-label with the session label of the backup. For example, my_backup_session_label.

    • To use xfsrestore interactively, use the -i option.

      The interactive dialog begins after xfsrestore finishes reading the specified device. Available commands in the interactive xfsrestore shell include cd, ls, add, delete, and extract; for a complete list of commands, use the help command.

Example 24.1. Restoring Multiple XFS File Systems

  • To restore the XFS backup files and save their content into directories under /mnt/:

    # xfsrestore -f /backup-files/boot.xfsdump /mnt/boot/
    # xfsrestore -f /backup-files/data.xfsdump /mnt/data/
  • To restore from a tape device containing multiple backups, specify each backup by its session label or session ID:

    # xfsrestore -L "backup_boot" -f /dev/st0 /mnt/boot/
    # xfsrestore -S "45e9af35-efd2-4244-87bc-4762e476cbab" \
                 -f /dev/st0 /mnt/data/

Additional resources

  • xfsrestore(8) man page.

24.3. Informational messages when restoring an XFS backup from a tape

When restoring a backup from a tape with backups from multiple file systems, the xfsrestore utility might issue messages. The messages inform you whether a match of the requested backup has been found when xfsrestore examines each backup on the tape in sequential order. For example:

xfsrestore: preparing drive
xfsrestore: examining media file 0
xfsrestore: inventory session uuid (8590224e-3c93-469c-a311-fc8f23029b2a) does not match the media header's session uuid (7eda9f86-f1e9-4dfd-b1d4-c50467912408)
xfsrestore: examining media file 1
xfsrestore: inventory session uuid (8590224e-3c93-469c-a311-fc8f23029b2a) does not match the media header's session uuid (7eda9f86-f1e9-4dfd-b1d4-c50467912408)
[...]

The informational messages keep appearing until the matching backup is found.

24.4. Additional resources

  • xfsrestore(8) man page.