Backup a UNIX/Solaris UFS filesystem with ufsdump

Contributed by qmchenry May 17, 2006  
Tagged: UNIX

Many techniques exist for backing up data on UNIX systems. The ufsdump command is a powerful choice because it is free, already installed on most systems, has a wide array of options such as incremental backups, and is fast. This recipe will describe the simplest use of ufsdump: backing up a single filesystem to a file on disk.

The ufsdump command can be intimidating (particularly if you just read the man page). For simple backups, most options are not relevant. For instance, to backup the /usr filesystem to a file called /data/usr.ufs, use this command:

ufsdump 0f /data/usr.ufs /usr

The 0 (zero) option determines the dump level of the backup. 0 indicates a full backup while 1-9 are used for incremental backups. The f option, like with tar, tells ufsdump which file to use to dump the data to (just like the tar command). The last argument (/usr) specifies the target to be backed up. It can be specified as a filesystem path (such as /usr) or the raw device path (like /dev/rdsk/c1t0d0s4).

The command generates some interesting output during the backup. For example, the output of the command above might look like this:

DUMP: Date of this level 0 dump: Wed 17 May 2006 02:06:11 PM CDT
DUMP: Date of last level 0 dump: the epoch
DUMP: Dumping /dev/rdsk/c1t0d0s4 (techrx:/usr) to /data/usr.ufs.
DUMP: Mapping (Pass I) [regular files]
DUMP: Mapping (Pass II) [directories]
DUMP: Writing 32 Kilobyte records
DUMP: Estimated 2730660 blocks (1333.33MB).
DUMP: Dumping (Pass III) [directories]
DUMP: Dumping (Pass IV) [regular files]
DUMP: 2730622 blocks (1333.31MB) on 1 volume at 11356 KB/sec
DUMP: DUMP IS DONE

While this example demonstrates backing up a whole filesystem, it is also possible to backup a subset of a filesystem like a specific directory tree or a single file.