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vdump(8)							     vdump(8)



NAME

  vdump, rvdump	- Performs full	and incremental	backups	on filesets

SYNOPSIS

  /sbin/vdump -h

  /sbin/vdump -V

  /sbin/vdump -w

  /sbin/vdump [-0..9] [-CDNPUquv] [-F num_buffers] [-T tape_num] [-b size]
  [-f device] [-x num_blocks] fileset

  /sbin/rvdump -h

  /sbin/rvdump -V

  /sbin/rvdump -w

  /sbin/rvdump [-0..9] [-CDNUquv] [-F num_buffers] [-T tape_num] [-b size]
  [-f nodename:device] [-x num_blocks] fileset

OPTIONS

  -b size
      Specifies	the number of 1024-byte	blocks per record in the saveset. The
      valid range is 2 through 64 blocks; the default is 60 blocks per
      record.  The value of this option	also determines	the size of the	in-
      memory buffers.

  -C  Compresses the data as it	is backed up, which minimizes the saveset
      size.

  -D  Performs a level 0 backup	on the specified subdirectory.	This option
      overrides	any backup level specification in the command. If this option
      is specified, the	AdvFS user and group quota files and the fileset quo-
      tas are not backed up.

  -f device

  -f nodename:device
      Specifies	the destination	of the saveset.

      For vdump, the local destination can be a	device,	a file,	or, when the
      dash (-) character is specified, standard	output.

      For rvdump,  the mandatory specification is nodename:device to specify
      the remote machine name that holds the device or file.

  -F num_buffers
      Specifies	the number of in-memory	buffers	to use.	 The valid range is 2
      through 64 buffers; the default is 8 buffers.  The size of the in-
      memory buffers is	determined by the value	of the -b option.

  -h  Displays usage help for the command.

  -N  Does not rewind the storage device when it is a tape. Use	the -N option
      when you want to dump more than one saveset to a tape.

  -P  Produces backward-compatible savesets that can be	read by	earlier	ver-
      sions of the vrestore command.  However, some data, such as very large
      quota limits, can	be lost	in such	a saveset.

  -q  Displays only error messages; does not display information messages.

  -T tape_num
      Specifies	the starting number for	the first tape.	The default number is
      1. The tape number is used only to prompt	the operator to	load another
      tape in the drive.

  -u  Updates the /etc/vdumpdates file with a timestamp	entry from the begin-
      ning of the backup.

  -U  Does not unload the storage device when it is a tape.

  -v  Displays the names of the	files being backed up.

  -V  Displays the current version of the command.

  -w  Displays the filesets that have not been backed up within	one week.

  -x num_blocks
      Specifies	an "exclusive or" (XOR)	operation each time the	blocks speci-
      fied by num_blocks are written to	the saveset. The XOR operation is
      performed	on the blocks and the results written to the saveset as	an
      XOR block	that immediately follows the blocks. Subsequently, the vre-
      store command can	use this block to recover one of the blocks in the
      group should a read error	occur. The valid range is 1 through 32
      blocks; the default is 8 blocks. Using the -x option creates larger
      savesets and increases the amount	of time	required to back up a file
      system, but offers additional protection from saveset errors.

  -0..9
      Specifies	the backup level. The value 0 for this option causes the
      entire fileset to	be backed up to	the storage device.  The default
      backup level is 9.

OPERANDS

  fileset
      Specifies	the full path name of a	mounted	AdvFS fileset to be backed
      up. Alternatively, specifies a mounted NFS or UFS	file system. When
      used with	the -D option, specifies a subdirectory.

DESCRIPTION

  The vdump command backs up files and any associated extended attributes
  (including ACLs, see the proplist(4) and acl(4) reference pages) from	a
  single mounted fileset or clone fileset to a local storage device.

  The rvdump command backs up files and	any associated extended	attributes
  (including ACLs, see the proplist(4) and acl(4) reference pages) from	a
  single mounted fileset or clone fileset to a remote storage device.

  The vdump and	rvdump commands	are the	backup facility	for the	AdvFS file
  system. However, the commands	are file-system	independent, and you can use
  them to back up other	file systems, such as UFS and NFS.

  The commands back up all files in the	specified fileset that are new or
  changed since	a certain date and produce a saveset on	the storage device.
  The date is determined by comparing the specified backup level to previous
  backup levels	recorded in the	/etc/vdumpdates	file. The default storage
  device for the vdump command is /dev/tape/tape0_d1. You can specify an
  alternate storage device by using the	-f option.  There is no	default
  storage device for the rvdump	command; it must be specified.

  The commands perform either an incremental backup, level 9 to	1, or a	full
  backup, level	0, depending on	the desired level of backup and	the level of
  previous backups recorded in the /etc/vdumpdates file.

  Note that an incremental dump	only captures the files	that have changed,
  ignoring all others. This means that if you perform a	level 0	 dump and a
  later	incremental dump, deleted files	are not	marked as gone	(deleted). If
  you then do a	complete restore with a	level 0	saveset	and  incremental
  backups, the deleted files will be restored. You must	then  delete these
  files	individually.

  The commands back up all files that are new or have changed since the
  latest backup	date of	all backup levels that are lower than the backup
  level	being performed.  If a backup level that is lower than the specified
  level	does not exist,	the commands initiate a	level 0	backup.	A level	0
  backup backs up all the files	in the fileset.

  After	the backup operation is	complete, you can use the vrestore -t command
  to verify that the backup contains the files you wanted to save.  This com-
  mand lists the name and size of each file in the saveset without restoring
  them.

  When you specify the -C option, the commands back up the files with
  compression.	You cannot specify the compression ratio, it is	determined by
  the contents of the dump.

  When you specify the -u option, the commands enter a time-stamp entry	of
  that fileset and its backup level into the /etc/vdumpdates file.

  If a file-system entry with a	specific backup	level does not already exist
  in the /etc/vdumpdates file, the commands append the file with a new vdump
  record; otherwise, the commands overwrite the	existing record, changing the
  backup date to reflect the most current backup session. This occurs after
  all files in the named fileset have been successfully	backed up.

  If you use the -N option to vdump more than one saveset to a tape, see the
  vrestore command for information on restoring	a series of savesets from a
  tape.

  Archives that	were created prior to Tru64 UNIX Version 5.0 will be restored
  with the same	characteristics	they would have	if they	were restored on the
  earlier systems.  For	example, any UFS sparse	files archived with the	vdump
  command prior	to Tru64 UNIX Version 5.0 will be allocated disk space and
  filled with zeros and	any AdvFS striped sparse files archived	with the
  vdump	command	prior to Version 4.0D will be allocated	disk space and filled
  with zeros.

  Under	normal usage, the commands use a small amount of additional space on
  the storage device, typically	less than 1 percent, when a fileset is backed
  up. If the -x	option is used,	the amount of additional space used to back
  up the fileset increases because XOR blocks are written.

  If you use either of the commands to back up a fileset to an output file
  that is part of the fileset you are backing up, there	are two	results	you
  should be aware of:

    +  That output file	could be twice the size	it should be.

    +  When you	restore	that output file, you obtain only a partial copy of
       it.

  To inform you	of the situation, the commands display a message similar to
  the following:

       vdump: /demo/vdump.file is on the same device as	/demo, this
       vdump: could cause recursive back up problems.

       vdump: Do you want to abort the dump? (yes or no).

  Typically, you would want to abort the backup	operation and select another
  file on which	to back	up the fileset.	 However, there	may be situations
  when you do not want to abort	the operation. For example, if you are back-
  ing up a portion of a	fileset	using the -D option, you can store the
  resulting output file	in the same fileset in a section not being backed up.

RESTRICTIONS

  To run the rvdump command, you must be able to execute the rsh command on
  the remote node to which you are dumping.  See rsh(8)	for server and client
  access rules.

  You do not have to be	the root user to use the vdump or the rvdump command.

  The vdump and	rvdump commands	back up	only mounted filesets.

  Filesets backed up by	using the vdump	or the rvdump command must be
  restored by using the	vrestore or the	rvrestore command. The vdump and
  rvdump commands are not interchangeable with the dump	and rdump commands.
  Similarly, the vrestore and the rvrestore commands are not interchangeable
  with the restore and rrestore	commands.

  The AdvFS quota files	and fileset quotas in the fileset are included in a
  saveset when you are the root	user and a full	fileset	is saved. AdvFS	quota
  files	and fileset quotas can only be backed up for locally-mounted
  filesets.

  The vdump command is disabled	on filesets enabled for	the Data Management
  Application Programming Interface (DMAPI). Users should check	with the ven-
  dor of their data management (DM) application	for the	appropriate back up
  procedure to use.

  The vrestore command in DIGITAL UNIX versions	earlier	than Version 4.0 can-
  not be used to restore savesets produced by the vdump	command	in DIGITAL
  UNIX Version 4.0 or higher systems or	in Tru64 UNIX systems.

  If you want to use the vdump and rvdump commands to write a saveset on the
  a or c disk partition, and you have no data on any partitions	on that	disk,
  then you must	zero the disk label so vdump can write to partition a or c
  starting at block 0. If you have data	on any disk partitions,	then use a
  partition other than a or c. See "Duplicating	or Recovering a	System (Root)
  Disk"	in the System Administration.

  You can backup to partitions that do not start at block 0 (partition b for
  example) if the partition you	want to	dump to	is large enough	to hold	the
  data.	For more information about dumping to disk partitions see AdvFS
  Administration, Dumping to a File or Disk Partition.

  The /etc/vdumpdates file is written in ASCII and consists of a single
  record per line.  You	must be	the root user to update	this file or to
  change any record field.



				    Caution

       If you edit the /etc/vdumpdates file, be	certain	that all records fol-
       low the correct format. An incorrectly formatted	record in this file
       may make	the file inaccessible for updates or reads.

EXAMPLES

   1.  A typical /etc/vdumpdates file includes entries like the	following,
       defining	the fileset name, last backup level, and date:


	    dmn2#set2 8	Sat Apr	21 07:40:35 2001
	    dmn2#set2 9	Sun Apr	22 07:20:42 2001
	    dmn2#set2 3	Mon Apr	23 07:47:37 2001
	    dmn2#set2 7	Sun Apr	22 08:23:05 2001
	    /dev/disk/dsk0g 0 Thu Apr 26 12:11:42 2001

       In this example,	dmn2#set2 represents an	AdvFS fileset;
       /dev/disk/dsk0g represents a UFS	file system.  If you perform a level
       8 backup	of the dmn2#set2, using	this /etc/vdumpdates file, you can
       expect the following results:

	 +  The	vdump command ignores the /dev/disk/dsk0g entry	because	it
	    does not match the specified fileset, dmn2#set2.

	 +  The	vdump command ignores the level	8 and 9	entries	because	these
	    entries are	equal to or higher than	the level 8 backup you
	    requested.	This leaves only the level 3 and 7 entries.

	 +  Of the two remaining entries, the vdump command chooses the	entry
	    with the most recent dump date, which is the level 3 entry.

	 +  The	vdump command backs up all files that were created or modi-
	    fied after the dump	date of	the level 3 entry.

	 +  The	vdump command modifies the access time of each file in the
	    fileset.

   2.  To perform a full (level	0) backup of a local fileset to	a local	dev-
       ice, enter a command similar to the following:
	    % vdump -0 -u -f /dev/tape/tape1_d6	/fs1

       In this example,	-0 specifies that all (level 0)	files in the fileset
       mounted at /fs1 will be backed up to /dev/tape/tape1_d6;	-u specifies
       that vdump will update the /etc/vdumpdates after	a successful backup
       of the fileset.

   3.  To perform a full level 0 backup	of a local fileset to a	remote dev-
       ice, enter a command similar to the following:
	    # rvdump -0	-u -f pease:/dev/tape/tape1_d6 /fs1

       In this example,	-0 specifies that all files in the fileset mounted at
       /fs1 will be backed up to the remote device /dev/tape/tape1_d6 on
       machine node pease; -u specifies	that rvdump will update	the
       /etc/vdumpdates file after a successful backup of the fileset.

   4.  When the	backup saveset device is the character - (dash), the vdump
       command writes to standard output.  Thus, the vdump and vrestore	com-
       mands can be used in a pipeline expression to copy filesets.   The
       following are typical commands; they are	equivalent:
	    # vdump -0 -f - /usr | (cd /mnt; vrestore -x -f -)
	    # vdump -0f	- /usr | vrestore -xf -	-D /mnt

       The rvdump and rvrestore	commands are unable to use the - (dash)	char-
       acter. The output device	must be	specified.

   5.  To dump more than one saveset on	a single tape, enter a command simi-
       lar to the following:
	    # vdump -N /dev/tape/tape0 fs1
	    # vdump -N /dev/tape/tape0 fs2

       In this example,	the -N option specifies	that the tape will not be
       rewound between saving the filesets.

   6.  For weekly tape backups,	a set of 5 tapes per backed up fileset can be
       used on a cyclical basis.  Each month a level 0 backup is taken on a
       set of fresh tapes that are saved until the next	level 0	backup.

       The following is	a guideline for	the level of backup to perform during
       weekly, biweekly, and monthly periods:


       ______________________________
		  M   Tu   W   Th   F
       ______________________________
       Weekly	  0   3	   2   5    4

       Biweekly	  0   3	   2   5    4
		  0   9	   8   9    9

       Monthly	  0   3	   2   5    4
		  1   9	   8   9    9
		  1   3	   2   5    4
		  1   9	   8   9    9
       ______________________________



FILES

  /sbin/vdump
      Specifies	the vdump command path.

  /sbin/rvdump
      Specifies	the rvdump command path.

  /etc/vdumpdates
      Contains a list of filesets that were backed up, the date	that each
      file system was backed up, and the backup	level.

  /etc/fstab
      Contains the full	path names and mount points of filesets.

SEE ALSO

  Commands: mount(8), umount(8), rsh(8), vrestore(8), rvrestore(8)

  Files: acl(4), proplist(4)

  AdvFS	Administration