vxdump, rvxdump - incremental VxFS file system dump, local or across
/usr/sbin/vxdump [-nuwW] [-0123456789] [-f filename] [-d density]
[-s size] [-T time] [-b blocksize] [-B records] filesystem
/usr/sbin/rvxdump [-nuwW] [-0123456789] [-f filename] [-d density]
[-s size] [-T time] [-b blocksize] [-B records] filesystem
/usr/sbin/vxdump option [argument ...] filesystem
/usr/sbin/rvxdump option [argument ...] filesystem
vxdump copies to magnetic tape all files in the vxfs filesystem that
have been changed after a certain date. This information is derived
from the files /var/adm/dumpdates and /etc/fstab. rvxdump copies the
files to a tape drive on a remote system. rvxdump runs a process,
/usr/sbin/rmt, on the remote machine to access the tape device.
vxdump and rvxdump support both getopt(3C) and traditional dump
command line invocations as shown above. The original dump command
line style is supported for compatibility with previous versions of
vxdump and for synonymy with the existing dump program used for hfs
file systems. For the traditional command line style, option consists
of characters from the set 0123456789bBdfnsTuWw without any
intervening white space.
On most devices vxdump detects end-of-media and prompts you to change
the media if there is insufficient space, so it is not necessary to
specify the size of the device. However, if the dump will require
multiple tapes and the tapes are to be read using an older version of
vxrestore, or if the tape device handles end-of-media in a way that
vxdump doesn't recognize, then you must specify the size of the device
using the -B option or a combination of the -d and -s options.
If no arguments are given, the options are assumed to be -9u and a
default file system is dumped to the default tape.
-number number is a single digit in the range [0-9] and
indicates the dump level. All files modified since the
last date stored in the file /var/adm/dumpdates for the
same file system at a lesser dump level will be dumped.
Thus, the option -0 dumps the entire file system. If
no date is determined by the level, the beginning of
(UNIX) time is assumed.
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The number of logical records per volume. The vxdump
logical record size is 1024 bytes. records can also be
specified with a suffix to indicate a unit of measure
other than 1024 bytes. You can append a k or K, m or
M, or g or G, to the number to indicate that the value
is in kilobytes, megabytes, or gigabytes, respectively.
This option overrides the calculation of tape size
based on length and density.
The blocking factor is taken from the blocksize option
argument. (default is 63 if -b is not specified).
Block size is defined as the logical record size times
the blocking factor. vxdump writes logical records of
1024 bytes. Older versions of vxdump used a blocking
factor of 10 for tapes with densities less than 6250
BPI, and 32 for tapes with densities of 6250 BPI or
greater. vxrestore dynamically determines the blocking
The density of the tape (expressed in BPI) used to
calculate the amount of tape used per tape reel. If -s
is specified, a default density value of 1600 is
assumed for a reel tape.
Place the dump on the file filename instead of the
tape. If the name of the file is -(dash), vxdump
writes to the standard output. This option can be of
the form machine:device to specify a tape device on a
-n Whenever vxdump requires operator attention, notify all
users in group operator by means similar to that
described by wall(1M).
-s size size is the size of the dump tape, specified in feet.
When the specified size is reached, vxdump waits for
reels to be changed. If -d is specified, a default
size value of 2300 is assumed for a reel tape.
-T date Use the specified date as the starting time for the
dump instead of the time determined from looking in
/var/adm/dumpdates. The format of date is the same as
that of ctime(3C) This option is useful for automated
dump scripts that wish to dump over a specific period
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+ You can specify -T only for incremental dumps; using
-T for a level 0 dump returns an error.
+ -T is mutually exclusive with the -u option.
+ If you enter an improperly formatted date, -T
returns an error message and terminates the dump.
-u If the dump completes successfully, write on file
/var/adm/dumpdates the date when the dump started.
This file records a separate date for each file system
and each dump level. The format of /var/adm/dumpdates
is user-readable and consists of one free-format record
per line: file system name, increment level and dump
date in ctime(3C) format. The file /var/adm/dumpdates
can be edited to change any of the fields if necessary.
-W For each file system in /var/adm/dumpdates, print the
most recent dump date and level, indicating which file
systems should be dumped. If -W is specified, all
other options are ignored and vxdump exits immediately.
-w Operate like -W, but print only file systems that need
to be dumped.
vxdump requires operator intervention for any of the following
+ end of tape
+ end of dump
+ tape-write error
+ tape-open error
+ disk-read error (if errors exceed threshold of 32).
In addition to alerting all operators implied by the -n option, vxdump
interacts with the control terminal operator by posing questions
requiring yes or no answers when it can no longer proceed or if there
is a serious problem.
Because making a full dump typically requires considerable time,
vxdump establishes a checkpoint at the start of each tape volume. If,
for any reason, writing that volume fails, vxdump, with operator
permission, restarts from the checkpoint after the old tape is rewound
and removed and a new tape is mounted.
vxdump periodically reports information to the operator, including
estimates (typically low) of the number of blocks to write, the number
of tapes it requires, time required to complete, and the time
remaining until tape change. The output is verbose to inform other
users that the terminal controlling vxdump is busy and will be for
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The dump tape format is independent of the VxFS disk layout. A dump
of a file system with the Version 4 disk layout can be restored on a
file system using the Version 2 disk layout or even a file system of
another file system type, with the following exceptions:
+ Files larger than 2 GB cannot be restored by earlier versions of
vxrestore. If a file larger than 2 GB is encountered, an older
vxrestore skips the file and returns this message:
Resync restore, skipped num blocks
+ Files larger than 2 GB cannot be restored on a file system that
does not support large files (see mount_vxfs(1M)).
+ A file with a large uid (user ID of the file owner) or large gid
(group ID of the file owner) cannot be restored correctly on a file
system that does not support large IDs. Instead, the owner and/or
group of the file will be that of the user invoking vxrestore. (A
large ID is a value greater than 65535. The VxFS Version 2 disk
layout does not support large IDs).
+ Files with VxFS extent attributes (see setext(1M)) cannot be
restored on a file system of a type that does not support extent
If you use vxdump to produce a dump intended for an earlier version of
vxrestore, and if the dump requires multiple tapes, you should use the
-s, -d, or -B option.
Dumps produced by older versions of vxdump can be read by the current
version of vxrestore.
Perform dumps with the file system unmounted or the system in single-
user environment (see init(1M)) to ensure a consistent dump. If you
have the HP OnLineJFS product installed, the dump can be performed in
the multi-user environment using a snapshot file system with the
online backup facility (see the snapof=file option of mount_vxfs(1M)).
Up to 32 read errors on the file system are ignored.
Each reel requires a new process; parent processes for reels already
written remain until the entire tape is written.
vxdump does not dump information about ACLs, therefore vxrestore does
not restore information about ACLs.
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A version of vxdump resides in /sbin for use when the system is in
single user state.
In the following example, assume that the file system /mnt is normally
attached to the file tree at the root directory, (/).
In this example, the entire file system (/mnt) is dumped on
/dev/rmt/0m and the size of the tape is 2 gigabytes.
vxdump -0 -B 2g -f /dev/rmt/0m /mnt
Using the traditional command line syntax and specifying the tape size
in logical records:
vxdump 0Bf 2097152 /dev/rmt/0m /mnt
The option argument 2097152 goes with the option letter B as it is the
first option letter that requires an option argument. The option
argument /dev/rmt/0m goes with the option letter f as it is the second
option letter that requires an option argument.
vxdump and rvxdump are based on the dump and rdump programs from the
4.4 Berkeley Software Distribution, developed by the the University of
California, Berkeley, and its contributors.
/dev/rmt/0m Default tape unit to dump to.
/var/adm/dumpdates New format-dump-date record.
/etc/fstab Dump table: file systems and frequency.
/etc/mnttab Mounted file system table.
/etc/group Used to find group operator.
close(2) ctime(3C) dump(1M), fstab(4), getopt(3C), init(1M),
mount_vxfs(1M), open(2) rmt(1M), setext(1M), vxrestore(1M), wall(1M).
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