dump2(1M) DG/UX 4.30 dump2(1M)
NAME
dump2 - incremental file system backup
SYNOPSIS
dump2 [ options ] file-system
DESCRIPTION
dump2 creates a data file of all files changed after a
certain date in a particular file system. file-system is
the pathname of a special file referring to a device
containing a file system. Note that file-system must refer
to a local file system (not a file system mounted from
another host).
File system dumps created with dump2 can be read by
restore(1M)
Options:
-dump-level
Indicate the dump level (0 through 9). 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 Jan. 1, 1970, GMT,
is assumed; thus the dump-level 0 dumps the entire
file system. The default is 9.
-B number-of-buffers
Specify number-of-buffers as the number of shared
memory buffers to use. A larger number may
increase the speed of dumps. The default is 3.
-b buffer-size
Specify buffer-size to be the number of 1024-byte
blocks written per record. For tape devices which
require blocking factors, this argument should
match the optimal blocking factor for the
particular device in use. The default is 10; the
maximum is 64.
-D output-disk-file-name
Write the output to output-disk-file-name without
any tape headers or trailers. This output can be
used as input for another dump by specifying the
-T option.
-f dump-device
Place the dump on dump-device. The default is
/dev/rmt/0. If you have DG TCP/IP (DG/UX), you
can use this option to dump to a remote device.
For example,
Licensed material--property of copyright holder(s) Page 1
dump2(1M) DG/UX 4.30 dump2(1M)
dump2 -0 -f sys:/dev/rmt/0 /dev/rdsk/root
lets you dump the root filesystem to the tape
device "0" on system "sys." To do this, you must
be logged in as root on your own sytsem, and your
system must have an entry in the remote host's
/.rhosts file.
-i Ignore tape size estimates. This allows dump2 to
write to the physical end of tape, rather than
stopping when the estimate indicates that end of
tape is near.
-M medium-name
Specify medium-name as the type of medium being
dumped to. medium-name must be an entry in the
tape table file (see the -t option).
-n Notify an operator (as in wall(1M)) whenever a
response is required at the operator's console.
/etc/group must contain an entry for "operator".
-T input-file-name
Read filesystem information from input-file-name.
This file must be in the form produced by running
dump2 with the -D option.
-t tape-table-file-name
Read medium information from tape-table-file-name.
The default is /etc/dumptab.
-u Write the date of the beginning of the dump on the
file /etc/dumpdates, if the dump completes
successfully. This file records a separate date
for each file system and each dump level. The
/etc/dumpdates file consists of one free format
record per line: file system name, increment
level, and ctime(3)-format dump date.
-z Print the inode numbers of dumped files on the
standard output.
dump2 and restore support symbolic links and control point
directories.
dump2 requires operator intervention on end of tape, end of
dump, tape write error, tape open error, or disk read error
(if there are more than 32 errors). In addition to alerting
all operators (with the -n option), dump2 interacts with the
operator on the dump2 command's control terminal when dump2
can no longer proceed, or if something is grossly wrong.
All questions dump2 poses must be answered by typing yes or
Licensed material--property of copyright holder(s) Page 2
dump2(1M) DG/UX 4.30 dump2(1M)
no.
Because making a full dump involves a lot of time and
effort, dump2 allows the dump to continue if a bad tape
block is encountered. If at any point dump2 fails to write
to the tape, dump2 will prompt the operator for a new tape,
and continue the dump.
At periodic intervals, dump2 tells the operator what is
going on, usually including 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 dump2 is busy and will be for some time.
DUMP CYCLES
To perform dumps, start with a full level 0 dump:
dump2 -0un /dev/rdsk/root
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 ...
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,
which is saved indefinitely, is taken on a set of fresh
tapes.
FILES
/etc/dumpdates Previous dump dates for each file system
/etc/fstab Dump frequency for each file system
/etc/group Group entry for "operator"
/etc/dumptab Table specifying media characteristics
SEE ALSO
restore(1M), dumptab(4), fstab(4), and group(4).
NOTES
dump2 uses the -B and -b arguments to request approximately
number-of-buffers * buffer-size * 1024 bytes of shared
memory. If dump2 cannot get this amount of shared memory,
either or both of these arguments should be decreased.
Alternatively, the system can be reconfigured to make more
shared memory available.
Licensed material--property of copyright holder(s) Page 3