vxdump(1M)

NAME

vxdump, rvxdump — incremental VxFS file system dump, local or across network

SYNOPSIS

vxdump [-cnouwW] [-0123456789] [-b blocksize] [-B records] [-d density] [-f filename] [-s size] [-T time] filesystem

rvxdump [-cnouwW] [-0123456789] [-b blocksize] [-B records] [-d density] [-f filename] [-s size] [-T time] filesystem

vxdump option [argument ...] filesystem

rvxdump option [argument ...] filesystem

DESCRIPTION

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 /etc/fstab and a timestamp file, by default /etc/dumpdates. 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 0123456789bBdfonsTuWw 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.

Options

If no arguments are given, the options are assumed to be -9u and a default file system is dumped to the default tape.

vxdump recognizes the following options:

-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 timestamp file 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.

-B records

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.

-b blocksize

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 factor.

-c

Cartridge. Specifies using a cartridge instead of the standard half-inch reel. This sets the density to 1000 BPI and the blocking factor to 63. The length is set to 425 feet. -c is incompatible with the -d option, unless you specify a density of 1000 BPI with that option.

-d density

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.

-f filename

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 remote machine.

-n

Whenever vxdump requires operator attention, notify all users in group operator by means similar to that described by wall(1M).

-o

Use /etc/vxdumpdates rather than /etc/dumpdates for timestamp information.

-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 the timestamp file. 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 of time.

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 in the timestamp file the date when the dump started. This file records a separate date for each file system and each dump level. The format of the timestamp file 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 timestamp file can be edited to change any of the fields if necessary. The -u option is ignored for partial dumps.

-W

For each file system in the timestamp file 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.

Operands

vxdump recognizes the following operand:

filename: Name of the file that contains a list of all files in the vxfs filesystem to be copied to magnetic tape.

Operator Interaction

vxdump requires operator intervention for any of the following conditions:

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 some time.

Compatibility

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 attributes.

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.

Notes

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.

Neither vxdump nor vxrestore work with Storage Checkpoints.

A version of vxdump resides in /sbin for use when the system is in single user state.

EXAMPLES

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.

AUTHOR

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.

FILES

/dev/rmt/0m: Default tape unit to dump to.
/etc/dumpdates: New format-dump-date record. This is the default file for VxFS.
/etc/vxdumpdates: New format-dump-date record. Can be substituted for /etc/dumpdate by using the /CR -o option.
/etc/fstab: Dump table: file systems and frequency.
/etc/mnttab: Mounted file system table.
/etc/group: Used to find group operator.