8.7. Backup and Restoration of XFS File Systems XFS file system backup and restoration involves two utilities: xfsdump and xfsrestore . To backup or dump an XFS file system, use the xfsdump utility. Red Hat Enterprise Linux 6 supports backups to tape drives or regular file images, and also allows multiple dumps to be written to the same tape. The xfsdump utility also allows a dump to span multiple tapes, although only one dump can be written to a regular file. In addition, xfsdump supports incremental backups, and can exclude files from a backup using size, subtree, or inode flags to filter them. In order to support incremental backups, xfsdump uses dump levels to determine a base dump to which a specific dump is relative. The -l option specifies a dump level ( 0-9 ). To perform a full backup, perform a level 0 dump on the file system (that is, /path/to/filesystem ), as in: Note The -f option specifies a destination for a backup. For example, the /dev/st0 destination is normally used for tape drives. An xfsdump destination can be a tape drive, regular file, or remote tape device. In contrast, an incremental backup will only dump files that changed since the last level 0 dump. A level 1 dump is the first incremental dump after a full dump; the incremental dump would be level 2 , and so on, to a maximum of level 9 . So, to perform a level 1 dump to a tape drive: Conversely, the xfsrestore utility restores file systems from dumps produced by xfsdump . The xfsrestore utility has two modes: a default simple mode, and a cumulative mode. Specific dumps are identified by session ID or session label . As such, restoring a dump requires its corresponding session ID or label. To display the session ID and labels of all dumps (both full and incremental), use the -I option: This will provide output similar to the following: Example 8.4. Session ID and labels of all dumps Simple Mode for xfsrestore The simple mode allows users to restore an entire file system from a level 0 dump. After identifying a level 0 dump's session ID (that is, session-ID ), restore it fully to /path/to/destination using: Note The -f option specifies the location of the dump, while the -S or -L option specifies which specific dump to restore. The -S option is used to specify a session ID, while the -L option is used for session labels. The -I option displays both session labels and IDs for each dump. Cumulative Mode for xfsrestore The cumulative mode of xfsrestore allows file system restoration from a specific incremental backup, for example, level 1 to level 9 . To restore a file system from an incremental backup, simply add the -r option: Interactive Operation The xfsrestore utility also allows specific files from a dump to be extracted, added, or deleted. To use xfsrestore interactively, use the -i option, as in: xfsrestore -f /dev/st0 -i The interactive dialogue will begin after xfsrestore finishes reading the specified device. Available commands in this dialogue include cd , ls , add , delete , and extract ; for a complete list of commands, use help . For more information about dumping and restoring XFS file systems, refer to man xfsdump and man xfsrestore .

Commands:
xfsdump -l 0 -f /dev/ device /path/to/filesystem
xfsdump -l 1 -f /dev/st0 /path/to/filesystem
xfsrestore -I
file system 0: fs id: 45e9af35-efd2-4244-87bc-4762e476cbab session 0: mount point: bear-05:/mnt/test device: bear-05:/dev/sdb2 time: Fri Feb 26 16:55:21 2010 session label: "my_dump_session_label" session id: b74a3586-e52e-4a4a-8775-c3334fa8ea2c level: 0 resumed: NO subtree: NO streams: 1 stream 0: pathname: /mnt/test2/backup start: ino 0 offset 0 end: ino 1 offset 0 interrupted: NO media files: 1 media file 0: mfile index: 0 mfile type: data mfile size: 21016 mfile start: ino 0 offset 0 mfile end: ino 1 offset 0 media label: "my_dump_media_label" media id: 4a518062-2a8f-4f17-81fd-bb1eb2e3cb4f xfsrestore: Restore Status: SUCCESS
xfsrestore -f /dev/st0 -S session-ID /path/to/destination
xfsrestore -f /dev/st0 -S session-ID -r /path/to/destination