DUMP(VIII) 11/24/73 DUMP(VIII)
NAME
dump - incremental file system dump
SYNOPSIS
dump [ key [ arguments ] filesystem ]
DESCRIPTION
Dump makes an incremental file system dump on magtape of all
files changed after a certain date. The key argument
specifies the date and other options about the dump. Key
consists of characters from the set abcfiu0hds.
a Normally files larger than 1000 blocks are not
incrementally dump; this flag forces them to be dumped.
b The next argument is taken to be the maximum size of
the dump tape in blocks (see s).
c If the tape overflows, increment the last character of
its name and continue on that drive. (Normally it asks
you to change tapes.)
f Place the dump on the next argument file instead of
the tape.
i the dump date is taken from the entry in the file
/etc/dtab corresponding to the last time this file
system was dumped with the -u option.
u the date just prior to this dump is written on
/etc/dtab upon successful completion of this dump.
This file contains a date for every file system dumped
with this option.
0 the dump date is taken as the epoch (beginning of
time). Thus this option causes an entire file system
dump to be taken.
h the dump date is some number of hours before the
current date. The number of hours is taken from the
next argument in arguments.
d the dump date is some number of days before the
current date. The number of days is taken from the
next argument in arguments.
s the size of the dump tape is specified in feet. The
number of feet is taken from the next argument in
arguments. It is assumed that there are 9 standard
UNIX records per foot. When the specified size is
reached, the dump will wait for reels to be changed.
The default size is 2200 feet.
If no arguments are given, the key is assumed to be i and
the file system is assumed to be /dev/rp0.
Full dumps should be taken on quiet file systems as follows:
dump 0u /dev/rp0
ncheck /dev/rp0
The ncheck will come in handy in case it is necessary to
restore individual files from this dump. Incremental dumps
should then be taken when desired by:
dump
When the incremental dumps get cumbersome, a new complete
dump should be taken. In this way, a restore requires
loading of the complete dump tape and only the latest
incremental tape.
DIAGNOSTICS
If the dump requires more than one tape, it will ask you to
change tapes. Reply with a new-line when this has been
done. If the first block on the new tape is not writable,
e.g. because you forgot the write ring, you get a chance to
fix it. Generally, however, read or write failures are
fatal.
FILES
/dev/mt0 magtape
/dev/rp0 default file system
/etc/dtab
SEE ALSO
restor (VIII), ncheck (VIII), dump (V)
BUGS