ufsdump(1M)

ufsdump -- incremental filesystem dump

Synopsis

/usr/sbin/ufsdump [options [arguments]] filesystem

Description

ufsdump backs up all files in filesystem, where filesystem represents a special device, or files changed after a certain date, to magnetic tape; options is a string that specifies ufsdump options, as shown below. Any arguments supplied for specific options are given as subsequent words on the command line, in the same order as that of the options listed.

If no options are given, the default is 9u.

Command options

0-9

The dump level. All files in the filesystem that have been modified since the last ufsdump at a lower dump level are copied to the volume. For instance, if you did a level 2 dump on Monday, followed by a level 4 dump on Tuesday, a subsequent level 3 dump on Wednesday would contain all files modified or added since the level 2 (Monday) backup. A level 0 dump copies the entire filesystem to the dump volume.

b factor

Blocking factor. Specify the blocking factor for tape writes. The default is 20 blocks per write.

NOTE: The blocking factor is specified in terms of 512-byte blocks, for compatibility with tar.

The default blocking factor for tapes of density 6250BPI and greater is 64. The default blocking factor for cartridge tapes (c option specified) is 126. The highest blocking factor available with most tape drives is 126.

c

Cartridge. Use a cartridge instead of the standard half-inch reel. This sets the density to 1000BPI and the blocking factor to 126. The length is set to 425 feet. This option is incompatible with the d option, unless you specify a density of 1000BPI with that option.

d bpi

Tape density. The density of the tape, expressed in BPI, is taken from bpi. This is used to keep a running tab on the amount of tape used per reel. The default density is 1600 except for cartridge tape. Unless a higher density is specified explicitly, ufsdump uses its default density -- even if the tape drive is capable of higher-density operation (for instance, 6250BPI).

NOTE: The density specified should correspond to the density of the tape device being used, or ufsdump will not be able to handle end-of-tape properly.

f dump-file

Dump file. Use dump-file as the file to dump to, instead of /dev/rmt*. If dump-file is specified as -, dump to the standard output.

n

Notify all operators in the operator group that ufsdump requires attention by sending messages to their terminals, in a manner similar to that used by the wall command.

s size

Specify the size of the volume being dumped to. When the specified size is reached, ufsdump waits for you to change the volume. ufsdump interprets the specified size as the length in feet for tapes and cartridges, and as the number of 1024-byte blocks for diskettes. The following are defaults:

cartridge: 425 feet
diskette: 1422 blocks (corresponds to a 1.44 Mb diskette, with one cylinder reserved for bad block information)

t tracks

Specify the number of tracks for a cartridge tape. The default is 9 tracks. The t option is not compatible with the D option.

u

Update the dump record. Add an entry to the file /etc/dumpdates, for each filesystem successfully dumped that includes the filesystem name, date, and dump level. This file can be edited by a privileged user.

w

List the filesystems that need backing up. This information is gleaned from the files /etc/dumpdates and /etc/vfstab. When the w option is used, all other options are ignored. After reporting, ufsdump exits immediately.

W

Similar to the w option, except that the W option includes all filesystems that appear in /etc/dumpdates, along with information about their most recent dump dates and levels. File systems that need backing up are highlighted.

Files

/dev/rmt*: default unit to dump to
/etc/dumpdates: dump date record
/etc/group: to find group operator
/etc/hosts

References

df(1M), shutdown(1M), tar(1), ufsrestore(1M), wall(1M)

Notices

Fewer than 32 read errors on the filesystem are ignored.

Each reel requires a new process, so parent processes for reels already written just hang around until the entire tape is written.

It is recommended that incremental dumps also be performed with the system running in single-user mode.