dump(8) System Manager's Manual dump(8)
dump - create file system dump
/etc/dump [ key [ argument... ] filesystem ]
The command copies all files changed after a certain date from a specified filesystem to a file, a pipe, magnetic tapes, or disks. The key
specifies the date and other options to be used by
Dumping a filesystem requires operator attention. An operator must intervene when the end of a tape or disk is reached, when the end of
the occurs, or when an unrecoverable input disk read error occurs (if more than 32 read errors occur). In addition to alerting all opera-
tors in the operator group, interacts with the operator at the control terminal when can no longer proceed, or if something is grossly
wrong. All questions that poses must be answered by typing yes or no.
Because a full dump uses considerable system time, checkpoints itself at the start of each tape or disk volume. If writing that volume
fails, asks the operator to restart from the checkpoint after the present tape or disk has been replaced.
The utility reports to the operator periodically, giving usually low estimates of the number of blocks to write, the number of tapes or
disks the dump will take, the time to completion, and the time until the tape or disk must be changed. The output is verbose, so that oth-
ers know that the terminal controlling is busy, and will be for some time.
This utility supports EOT handling which allows the use of multiple media. The utility prompts for the next volume when it encounters the
end of the current volume.
With the command, you specify a string of one or more of the options described below. If no options are specified, the key 9u is assumed.
0-9 Specifies the dump level. All files that were modified since the last date stored in the file for the same filesystem at lesser
levels will be dumped. If no date is determined by the level, the beginning of time is assumed. Thus, the level 0 causes the
entire filesystem to be dumped.
B Indicates that the next argument is a number that specifies the size, in 1024-byte blocks, of a storage medium, such as a diskette
or removable disk cartridge. See the first example.
d Indicates that the density of the tape, expressed in bits per inch, is taken from the next argument. This density is used in cal-
culating the amount of tape used per reel. The default density is 1600 bpi.
f Places the dump on the file or device specified by the next argument. If the name of the file is -, writes to standard output.
The default dump device is
n Notifies, by means similar to a command, all users in the group operator when needs operator attention.
S Prints output file size in bytes, or number of volumes for devices. See the third example.
s Indicates that the next argument specifies the size of the dump tape, in feet. When the specified size is reached, waits for the
reel to be changed. The default tape size is 2300 feet.
u Writes the date of the beginning of the dump on the file if the completes successfully. This file records a separate date for each
filesystem and each dump level. The format of consists of one free format record per line: filesystem name, increment level and
format dump date. The superuser can carefully edit to change any of the fields.
W Tells the operator which file systems need to be dumped. This information is taken from the files and The W option causes to print
out, for each file system in the most recent dump date and level, and highlights those file systems that should be dumped. If the
W option is used, all other options are ignored, and exits immediately.
w Lists only those filesystems that need to be dumped.
This example dumps the filesystem to RX50 diskettes. The option is needed when running to read this dump.
dump 9Bf 400 /dev/rra2a /dev/ra0a
This example dumps the filesystem to a 6250 bpi tape on a TU78 tape drive:
dump 0undf 6250 /dev/rmt?h /usr/users
This example reports number of bytes to be output for a level 0 dump of the root file system. Please note: the file test is not created.
dump 0Sf test /
The programs returns a 1 on successful completion.
Sizes are based on 1600-bpi blocked tape.
Anything fewer than 32 read errors on the filesystem are ignored.
Each reel requires a new process, so parent processes for reels already written remain until the entire tape is written.
Default filesystem to dump from
Default tape unit to dump to
Dump date record
Dump table: file systems and frequency
Operator group definition
Required for user interface
dump(5), fstab(5), opser(8), restore(8), rrestore(8c)
Guide to Backup and Restore