dump, rdump - incremental file system dump, local or across network
[option [argument ...] filesystem]
[option [argument ...] filesystem]
The and commands copy to magnetic tape all files in the filesystem that
have been changed after a certain date. This information is derived
from the files and option specifies the date and other options about
the dump. option consists of characters from the set The and commands
work only on file systems of type If the given file system is not of
type and will abort after printing an error message.
This number is the "dump level".
All files modified since the last date stored in file
for the same file system at lesser levels will be
dumped. If no date is determined by the level, the
beginning of time is assumed. Thus, the option causes
the entire file system to be dumped.
The blocking factor is taken from the next argument
(default is 10 if not specified). Block size is
defined as the logical record size times the blocking
factor. writes logical records of 1024 bytes. When
dumping to tapes with densities of 6250 BPI or greater
without using the option, the default blocking factor
The density of the tape (expressed in BPIs)
is taken from the next argument. This is used in cal‐
culating the amount of tape used per reel. The
default value of 1600 assumes a reel tape.
Place the dump on the next
argument file instead of the tape. If the name of the
file is writes to the standard output. When using
this option should be specified, and the next argument
supplied should be of the form
Whenever and require operator attention, notify all users in
group by means similar to that described by wall(1).
The size of the dump tape is specified in feet.
The number of feet is taken from the next argument.
When the specified size is reached, and wait for reels
to be changed. The default tape size value of 2300
feet assumes a reel tape.
If the dump completes successfully,
write on file the date when the dump started. This
file records a separate date for each file system and
each dump level. The format of is user-readable and
consists of one free-format record per line: file sys‐
tem name, increment level, and dump date in ctime(3C)
format. The file can be edited to change any of the
fields if necessary.
For each file system in
print the most recent dump date and level, indicating
which file systems should be dumped. If the option is
set, all other options are ignored and exits immedi‐
but prints only file systems that need to be dumped.
If no arguments are given, option is assumed to be and a default file
system is dumped to the default tape.
Sizes are based on 1600-BPI blocked tape; the raw magnetic tape device
must be used to approach these densities. Up to 32 read errors on the
file system are ignored. Each reel requires a new process; thus parent
processes for reels already written remain until the entire tape is
The command creates a server, or on the remote machine to access the
and require operator intervention for any of the following conditions:
· end of tape,
· end of dump,
· tape-write error,
· tape-open error, or
· disk-read error (if errors exceed threshold of 32).
In addition to alerting all operators implied by the option, and inter‐
act with the control terminal operator by posing questions requiring or
answers when it can no longer proceed or if something is grossly wrong.
Since making a full dump involves considerable time and effort, and
each establish a checkpoint at the start of each tape volume. If, for
any reason, writing that volume fails, and will, with operator permis‐
sion, restart from the checkpoint after the old tape has been rewound
and removed and a new tape has been mounted.
and periodically report information to the operator, including typi‐
cally low estimates of the number of blocks to write, the number of
tapes it will require, the time needed for completion, and the time
remaining until tape change. The output is verbose to inform other
users that the terminal controlling and is busy and will be for some
Access Control Lists (ACLs)
The optional entries of a file's access control list (ACL) are not
backed up with and Instead, the file's permission bits are backed up
and any information contained in its optional ACL entries is lost (see
In the following example, assume that the file system is to be attached
to the file tree at the root directory, This example causes the entire
file system to be dumped on and specifies that the density of the tape
is 6250 BPI.
will not backup a file system containing large files.
Tapes created from file systems containing files with UID/GIDs greater
than 60,000 will have a new magic number in the header to prevent older
versions of restore(1M) from incorrectly restoring ownerships for these
and were developed by the University of California, Berkeley.
Default file system to dump from.
Default tape unit to dump to.
New format-dump-date record.
Dump table: file systems and frequency.
Used to find group
SEE ALSOrestore(1M), rmt(1M), fstab(4), acl(5).