SysIII/usr/src/man/man1/dump.1m

.TH DUMP 1M Obsolescent
.SH NAME
dump \- incremental file system dump
.SH SYNOPSIS
.B dump
[ key [ arguments ] file-system ]
.SH DESCRIPTION
.I Dump\^
copies to magnetic tape all files
changed after a certain date
in the
.IR file-system .
The
.I key\^
specifies the date and other options about the dump.
.I Key\^
consists of characters from
the set
.BR 0123456789fusd .
.PP
.PD 0
.TP 5
.B  f
Place the dump on the next 
.I argument\^
file
instead of the tape.
.TP 5
.B  u
If the dump completes successfully,
write the date of the beginning of the dump on
file
.BR /etc/ddate .
This file records a separate date for
each file system and each dump level.
.TP 5
.B  0\-9
This number is the ``dump level''.
All files modified since the last date stored
in the file
.B /etc/ddate
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
.B 0
causes the entire file system to be dumped.
.TP 5
.B  s
The size of the dump tape is specified in feet.
The number of feet is taken from the next
.IR argument .
When the specified size is reached,
the dump will wait for reels to be changed.
The default size is 2,300 feet.
.TP 5
.B d
The density of the tape, expressed in
.SM BPI\*S,
is taken from the next
.IR argument .
This is used in calculating the amount of tape
used per write. The default is 1600.
.PD
.PP
.DT
If no arguments are given,
the
.I key\^
is assumed to be
.B 9u
and a default file system is dumped
to the default tape.
.PP
Now a short suggestion on how to
perform dumps.
Start with a full level-0 dump:
.BR "dump\ \|0u" .
Next,
periodic level-9 dumps should be made on an
exponential progression of tapes.
(Sometimes called Tower of Hanoi: 1, 2, 1, 3, 1, 2, 1, 4,\ .\|.\|.\|;
tape 1 used every other time,
tape 2 is used every fourth,
tape 3 is used every eighth, etc.):
.BR "dump\ \|9u" .
When the level-9 incremental approaches a full
tape (about 78,000 blocks at 1600
.SM BPI
blocked 20 blocks per record),
a level-1 dump should be made:
.BR "dump\ \|1u" .
After this,
the exponential series should progress as if uninterrupted.
These level-9 dumps are based on the level-1 dump, which
is based on the level-0 full dump.
This progression of levels of dumps can be carried
as far as desired.
.SH FILES
default file system and tape vary with installation.
.br
/etc/ddate: record dump dates of file system/level.
.SH SEE ALSO
cpio(1),
restor(1M),
volcopy(1M),
dump(5).
.SH DIAGNOSTICS
If the dump requires more than one tape,
it will ask you to change tapes.
Reply with a new-line after this has been done.
.SH BUGS
Sizes are based on 1600
.SM BPI
blocked tape.
The raw magnetic tape device has to be used to
approach these densities.
Read errors on the file system are ignored.
Write errors on the magnetic tape are usually fatal.