Chapter 18. Backing up an XFS file system
As a system administrator, you can use the
xfsdump to back up an XFS file system into a file or on a tape. This provides a simple backup mechanism.
18.1. Features of XFS backup
This section describes key concepts and features of backing up an XFS file system with the
You can use the
xfsdump utility to:
Perform backups to regular file images.
Only one backup can be written to a regular file.
Perform backups to tape drives.
xfsdumputility also enables you to write multiple backups to the same tape. A backup can span multiple tapes.
To back up multiple file systems to a single tape device, simply write the backup to a tape that already contains an XFS backup. This appends the new backup to the previous one. By default,
xfsdumpnever overwrites existing backups.
Create incremental backups.
xfsdumputility uses dump levels to determine a base backup to which other backups are relative. Numbers from 0 to 9 refer to increasing dump levels. An incremental backup only backs up files that have changed since the last dump of a lower level:
- To perform a full backup, perform a level 0 dump on the file system.
- A level 1 dump is the first incremental backup after a full backup. The next incremental backup would be level 2, which only backs up files that have changed since the last level 1 dump; and so on, to a maximum of level 9.
- Exclude files from a backup using size, subtree, or inode flags to filter them.
18.2. Backing up an XFS file system with xfsdump
This procedure describes how to back up the content of an XFS file system into a file or a tape.
- An XFS file system that you can back up.
- Another file system or a tape drive where you can store the backup.
Use the following command to back up an XFS file system:
# xfsdump -l level [-L label] \ -f backup-destination path-to-xfs-filesystem
Replace level with the dump level of your backup. Use
0to perform a full backup or
9to perform consequent incremental backups.
Replace backup-destination with the path where you want to store your backup. The destination can be a regular file, a tape drive, or a remote tape device. For example,
/backup-files/Data.xfsdumpfor a file or
/dev/st0for a tape drive.
Replace path-to-xfs-filesystem with the mount point of the XFS file system you want to back up. For example,
/mnt/data/. The file system must be mounted.
When backing up multiple file systems and saving them on a single tape device, add a session label to each backup using the
-L labeloption so that it is easier to identify them when restoring. Replace label with any name for your backup: for example,
- Replace level with the dump level of your backup. Use
Example 18.1. Backing up multiple XFS file systems
To back up the content of XFS file systems mounted on the
/data/directories and save them as files in the
# xfsdump -l 0 -f /backup-files/boot.xfsdump /boot # xfsdump -l 0 -f /backup-files/data.xfsdump /data
To back up multiple file systems on a single tape device, add a session label to each backup using the
# xfsdump -l 0 -L "backup_boot" -f /dev/st0 /boot # xfsdump -l 0 -L "backup_data" -f /dev/st0 /data
18.3. Additional resources