DUMPBSD(8,C) AIX Commands Reference DUMPBSD(8,C)
-------------------------------------------------------------------------------
dumpbsd
PURPOSE
Produces an incremental file system dump.
SYNTAX
+---------+
dumpbsd --- key ---| +-----+ |--- filesystem ---|
+-| d s |-+
^| f W ||
|| n w ||
|| u ||
|+-----+|
+-------+
Warning: See restrictions, Chapter 18, AIX Programming Tools and Interfaces.
DESCRIPTION
Note: The dumpbsd command is not used to port information between AIX and BSD
systems. The tar command is used for compatibility with BSD systems.
The dumpbsd command copies to magnetic tape all files changed after a certain
date in the filesystem. The key specifies the date and other options about the
dump. Key consists of characters from the set 0123456789fusdWn.
0-9 This number is the 'dump level'. All files modified since the last date
stored in the file /etc/dumpdates 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 0 causes the entire file
system to be dumped.
f Place the dump on the next argument file instead of the tape. If the
name of the file is "-," dumpbsd writes to standard output.
u If the dump completes successfully, write the date of the beginning of
the dump on file /etc/dumpdates. This file records a separate date for
each file system and each dump level. The format of /etc/dumpdates is
readable by people, consisting of one free format record per line: file
system name, increment level and ctime(3) format dump date.
/etc/dumpdates may be edited to change any of the fields, if necessary.
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DUMPBSD(8,C) AIX Commands Reference DUMPBSD(8,C)
s 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,
dumpbsd will wait for reels to be changed. The default tape size is
2300 feet.
d The density of the tape, expressed in BPI, is taken from the next
argument. This is used in calculating the amount of tape used per reel.
The default is 1600.
W dumpbsd tells the operator what file systems need to be dumped. This
information is gleaned from the files /etc/dumpdates and
/etc/filesystems. The W option causes dumpbsd to print out, for each
file system in /etc/dumpdates the most recent dump date and level, and
highlights those file systems that should be dumped. If the W option is
set, all other options are ignored, and dumpbsd exits immediately.
w Is like W, but prints only those file systems which need to be dumped.
n Whenever dumpbsd requires operator attention, notify by means similar to
a wall(1) all of the operators in the group "operator".
If no arguments are given, the key is assumed to be 9u and a default file
system is dumped to the default tape.
The dumpbsd command requires operator intervention on these conditions: end of
tape, end of dump, tape write error, tape open error or disk read error (if
there are more than a threshold of 32). In addition to alerting all operators
implied by the n key, dumpbsd interacts with the operator on dumpbsd's control
terminal at times when dumpbsd can no longer proceed, or if something is
grossly wrong. All questions dumpbsd poses must be answered by typing "yes" or
"no", appropriately.
Since making a dump involves a lot of time and effort for full dumps, dumpbsd
checkpoints itself at the start of each tape volume. If writing that volume
fails for some reason, dumpbsd will, with operator permission, restart itself
from the checkpoint after the old tape has been rewound and removed, and a new
tape has been mounted.
The dumpbsd command tells the operator what is going on at periodic intervals,
including usually low estimates of the number of blocks to write, the number of
tapes it will take, the time to completion, and the time to the tape change.
The output is verbose, so that others know that the terminal controlling
dumpbsd is busy, and will be for some time.
To perform dumps, start with a full level 0 dump:
dumpbsd 0un
Next, dumps of active file systems are taken on a daily basis, using a modified
Tower of Hanoi algorithm, with this sequence of dump levels:
3 2 5 4 7 6 9 8 9 9 ...
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DUMPBSD(8,C) AIX Commands Reference DUMPBSD(8,C)
For the daily dumps, a set of 10 tapes per dumped file system is used on a
cyclical basis. Each week, a level 1 dump is taken, and the daily Hanoi
sequence repeats with 3. For weekly dumps, a set of 5 tapes per dumped file
system is used, also on a cyclical basis. Each month, a level 0 dump is taken
on a set of fresh tapes that is saved forever.
The operator must add the following stanzas to the file system to be dumped
into /etc/filesystems.
mode The first stanza is the mode or type of file system described in these
terms:
rw read/write device
ro read only device
sw swap device
nm file system not normally mounted
xx ignore type
freq The second stanza is the dump frequency in days must be supplied by
giving a numerical value.
FILES
/dev/rrp1g Default file system to dump from.
/dev/rmt8 Default tape unit to dump to.
/etc/dumpdates New format dump date record.
/etc/filesystems Dump table: file systems and frequency.
/etc/group To find group "operator".
RELATED INFORMATION
See the following commands: "restorebsd" and "dump."
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