unixdev.net


Switch to SpeakEasy.net DSL

The Modular Manual Browser

Home Page
Manual: (OSF1-V5.1-alpha)
Page:
Section:
Apropos / Subsearch:
optional field



dump(8)								      dump(8)



NAME

  dump,	rdump -	Performs incremental file system dumps

SYNOPSIS

  /usr/sbin/dump [key[argument...] file	system]

  /usr/sbin/rdump -fdump_file [otherkey[argument...]file system]

  rdump

OPTIONS

  -0-9
      Specifies	the dump level.	 All files modified since the last time-stamp
      whose names are currently	stored in the /etc/dumpdates file for a	named
      file system at levels less than the one specified	are dumped to tape.
      When no time-stamp entry is defined for a	dump level, the	Epoch is
      assumed; thus, the value -0 for this key causes the entire file system
      to be dumped to the storage medium.

  -b blocks_per_write
      Specifies	the number of blocks in	1024 bytes to write to the storage
      medium.  The default write block value is	10 blocks (or 10 kilobytes).
      In many instances, increasing the	number of blocks per write will
      increase your dump performance.  For optimal results on Compaq's plat-
      form, use	a value	that is	greater	than or	equal to 32, is	a multiple of
      4, and is	less than 65.

  -c  The dump medium is a not a 9-track cartridge tape.

  -d density
      Specifies	the write density of the storage medium.  The density operand
      is expressed in bits per inch (bpi). This	information is used in calcu-
      lating the amount	of medium used per each	volume of the storage medium.
      For the dump command, the	density	will be	automatically provided by
      Compaq base system supported devices.  Otherwise,	the default write
      density for the dump and rdump commands is 1600 bpi.

  -f dump_file
      Writes the dump to the dump_file storage device instead of the default
      tape drive.  When	the name of dump_file is - (dash), the dump process
      writes to	standard output.  When	the  name of the dump_file is
      /dev/ntape/tape?*, the dump process will enable the -N option. When the
      rdump command is invoked,	the dump_file operand must specify both	the
      remote machine and the storage device in the format
      [user@]machine:device, where where user is an optional user identifica-
      tion (account) used to logon to the machine.  If you do not specify
      user rdump will use the user identification from the current process.
      The machine is the name or reference designation of the host machine,
      and device is the	name or	reference designation of the storage device.
      If you want to specify an	IPv6 address for machine, you must prefix the
      address with the \[ (backslash, left bracket) characters and terminate
      the address with the \] (backslash, right	bracket) characters.  Because
      the bracket characters are shell metacharacters, your must precede them
      with the backslash character.

  -L dump_label
      Specifies	the label of the dump to be displayed during restoration.
      The default label	is "No Label".	The label can be a maximum of 16
      characters.

  -n  Notifies,	by means of a command similar to wall(1), all operators	in
      the group	named operator,	which is specified in the /etc/group file
      whenever dump or rdump requires operator attention (to change a tape,
      for example).

  -s size
      Specifies	the size of a dump tape.  The size operand is expressed	in
      feet.  When the amount of	tape specified by size has been	written,
      either process waits for the  current reel to be changed (see the	-n
      option). For the dump command, the tape size will	be automatically pro-
      vided by Compaq base system supported devices.  Otherwise, the default
      tape size	for the	dump and rdump commands	is 2300	feet.

  -u  Writes the time of the beginning of the dump as the time-stamp entry in
      the /etc/dumpdates file for the file system record when the dump suc-
      cessfully	completes.

  -w  Tells an operator	what file systems must be dumped to the	storage	dev-
      ice.  This information is	obtained from the /etc/dumpdates and
      /etc/fstab files.	 The -w	key tells either process to print to the
      standard output a	record for each	file system listed in the
      /etc/dumpdates file.

  -B  Specifies	a block-mode device.  For the dump command, the	estimated
      calculations will	be based on the	device's storage capacity instead of
      density and size.

  -E  Prints the estimated size	of the dump file in 1-kilobyte blocks and the
      estimated	number of volumes that make up the dump	file, only. The	dump
      file will	be opened and closed, but nothing will be written to it.  The
      information will be output through standard error	and will have a	for-
      mat like the following:
	   23382 blocks, 0.04 volumes

      If the dump file is on disk, the format will be:
	   23382 blocks

      The operand placement will be preserved, but the exact words "blocks,"
      and "volumes" are	not guaranteed.	 Refer to the EXAMPLES section for
      further information.

  -N  Disables the rewinding of	the tape and placing the tape unit off line
      after completing the dump	session.  By default, when the dump command
      finishes backing up a file system	it rewinds the tape and	takes it off
      line.  For some tape subsystems, this tape will be ejected from the
      unit.  The -N option is the default when the dump_file operand is
      /dev/ntape/tape?.	If you use the -N option to dump to a regular file
      that does	not have the letters "rm" in its name, dump will inform	you
      of your error in using -N	and terminate.

  -S full_tape_size
      Specifies	output file size in feet.  When	the -B option is used, the
      full_tape_size operand specifies the output file size in number of
      1024-byte	blocks.

  -T tape_number
      Specifies	a tape number, which is	used in	the dialog with	the operator
      as the number of the first tape.

  -V  Prevents any extended attributes from being archived with	associated
      files.

  -W  Similar to -w, but for any file system listed in the /etc/dumpdates
      file, prints an output record and	highlights this	record with the	>>
      (greater than) character,	all files that must be dumped. When -W is
      specified, all other options are ignored and dump	exits immediately.

DESCRIPTION

  The dump command copies to the default /dev/tape/tape0_d0, or	to the alter-
  nate storage device specified	with the -f option, all	files and any associ-
  ated extended	attributes (including ACLs, see	the acl(4) and proplist(4)
  reference pages) changed after a certain date	in the specified local file
  system.

  The rdump command copies to the dump_file storage device all files and any
  associated extended attributes (including ACLs, see the acl(4) and pro-
  plist(4) reference pages) changed after a certain date in the	specified
  file system.

  These	commands cannot	be used	to archive AdvFS filesets.  See	vdump(8) for
  the operations used to archive AdvFS filesets.

  The dump and rdump commands are used to dump local files and any associated
  local	attributes from	a single file system defined by	the file system
  operand to a local or	remote storage device, respectively, where file	sys-
  tem contains the files you want to back up.

  The dump and rdump commands perform similar functions	with respect to
  storage of files contained in	the named file system. However,	the rdump
  command requires that	the -f option be used with any otherkey	and the	spe-
  cial dump_file operand.

  Both commands	copy all files in file system whose dump level is less than a
  specified value, and that have changed after a specified date	to the
  default storage device or to an alternate storage device. The	dump level
  and date are specified in the	local /etc/dumpdates file.  The	key and	argu-
  ment operand specify one or more options that	may be used to write files to
  the storage medium.  Characters permitted by the key operand are similar to
  options that consist of any of the characters	0123456789bcdfnsuwBNSTW	only,
  which	may be used in any logical combination,	but must be preceded with the
  - (dash) character; the argument operand specifies other options that	tell
  these	dump and rdump processes what to do.  These options are	described in
  the OPTIONS section.	Not all	keys permit argument options to	be specified.

  The /etc/dumpdates file consists of 3-column record lines that specify the
  file system name, a dump level, and a	standard time-stamp.  These processes
  enter	a time-stamp into the file system record after each file in the	named
  file system is successfully backed up.  The 3-column record in the
  /etc/dumpdates file contains the following information:

  1  File system name
      Lists the	file system device name.

  2  Dump level
      This is an integer between 1 and 9 that defines a	hierarchy for files
      in file system.  This hierarchy indicates	which files should be written
      to the storage medium when the dump or rdump command is executed.
      Level 0 defines all the files in file system.  When a level is
      assigned,	all files equal	to and less than that level in file system
      are backed up.

  3  Time-stamp
      The time-stamp tells the dump or rdump process when file system had its
      last backup.  This time-stamp is written by the dump or rdump process
      after the	specified file system backup is	completed.  When there is no
      time-stamp, the dump or rdump process assumes the	beginning of time
      (called the Epoch).

  The /etc/dumpdates file is written in	ASCII and consists of a	single record
  per line.  This file may be edited to	change any record field, when neces-
  sary.

  Either process requires operator intervention	when any of the	following
  conditions occur: end-of-tape, end-of-dump, tape-write error,	tape-open
  error, or when the number of disk-read errors	is greater than	32. In addi-
  tion to alerting all operators specified by the -n key, these	processes
  interact with	an operator at the terminal from which dump or rdump was
  invoked when either program can no longer proceed.

  All queries written to standard output by the	dump or	rdump process must be
  answered by typing yes or no on the invoking terminal.

  Because a dump to any	storage	medium requires	excessive time to process,
  each process checks itself at	the start of each storage volume.  In many
  instances, the default dump performance can be improved by modifying the
  number of blocks per write.  For additional information, see the descrip-
  tion for the -b switch in the	OPTIONS	section.

  When a volume	write fails, dump or rdump restarts itself from	the last suc-
  cessful checkpoint, with operator permission,	after the currently written
  storage medium is properly removed and another (replacement) storage medium
  has been mounted.

  These	processes also tell an operator	what is	going on at periodic inter-
  vals when writing to the storage medium.  This information consists of
  somewhat conservative	estimates for the number of blocks to write, the
  number of storage media that must be used for	the dump, the time to com-
  plete	the dump, and the time until the storage medium	must be	replaced with
  another one to complete the dump.  Output is verbose,	so that	others know
  that the terminal controlling	dump is	busy.  When processing takes place,
  the following	conditions apply:

    +  Fewer than 32 read errors during	a dump or rdump	tape-dump process are
       ignored.	 Each renewal of the storage medium requires a new dump	pro-
       cess, so	that parent processes for storage media	already	written	are
       in effect until the entire storage medium is written.

    +  When the	dump command has the W or w key	set, no	records	are written
       to the standard output for a file system	that has no current record in
       the /etc/dumpdates file,	even when listed in the	/etc/fstab file.

    +  When no argument	is specified, the key operand is assumed to be -9u so
       that the	default	file system is dumped to a default storage medium
       named /dev/tape/tape0_d0	(usually a tape).

  dump


  The dump command copies to the default /dev/tape/tape0_d0, or	to the alter-
  nate storage device specified	with the -f option, all	files changed after a
  certain date in the specified	local file system.







  rdump


  The rdump command copies to the dump_file storage device all files changed
  after	a certain date in the specified	file system.  This command is similar
  in operation to dump,	except that the	-f option is always specified (see
  the OPTIONS section) together	with any otherkey you may wish to specify.
  The dump_file	operand	should always be specified by machine name and device
  name as machine:device name.	If you want to specify an IPv6 address for
  machine, you must prefix the address with the	\[ (backslash, left bracket)
  characters and terminate the address with the	\] (backslash, right bracket)
  characters.

  The rdump command starts remote server /usr/sbin/rmt or /etc/rmt on the
  client machine to access the storage medium.

  Another vendor's rdump command may fail because rmt is not located in	/etc.
  To avoid this	problem, it may	be necessary to	provide	a symbolic link	on
  the machine pointing to /usr/sbin/rmt, as shown in the following example:

       ln -s /usr/sbin/rmt /etc/rmt

  Although the rdump command can detect	magnetic tape on remote	ULTRIX and
  Tru64	UNIX systems, it cannot	detect magnetic	tape on	other remote systems.
  Instead, it defaults to treating the output medium as	a disk file and
  aborts the operation should it encounter overflow or I/O error cases.

  Remote systems must be able to run the uname command if you are to use the
  rdump	command. If a remote system cannot run the uname command, you can set
  the environment variable OSF_RDUMP_SIMP_RCMD before you attempt the opera-
  tion.

NOTES

   1.  Estimates for dump and rdump.

       The information in this note is specific	to Compaq tape devices and
       the densities and sizes they use	under rdump. The size and density
       information is used to estimate the number of volumes required for the
       current dump or rdump request.  Some of the factors that	will effect
       the estimate calculation	include	the following:

	 +  Track format

	 +  Compression

	 +  Interrecord	gap size

	 +  Writing optimization technologies

	 +  Appending to a tape

       The estimate calculation	does not take these factors into account and
       can result in very large	(100-500%) miscalculations.  The estimates
       can be customized by adjusting the size in feet (-s) or size in 1024-
       byte block (-BS)	variables to the desired results.  The default values
       for /dev/tape/tape?_d0 devices used in the dump estimate	calculation
       are shown in the	following table:








       Tape Device   Density   Size	Size
		     (bpi)     (feet)

					(1024-byte
					blocks)

       TA78	     6250      1925	141056
       TA79	     6250      1925	141056
       TA81	     6250      1925	141056
       TA90	     38000     436	194560
       TA91	     38000     436	194560
       TF30	     6667      1182	92416
       TF70	     10000     2457	287948
       TF70L	     10000     2457	287948
       TK50	     6667      1182	92416
       TK70	     10000     2457	287948
       TKZ09	     54000     7456	4718592
       TLZ04	     61000     1584	1132646
       TLZ06	     61000     2640	1887436
       TLZ07	     61000     2640	1887436
       TS05	     1600      2075	38912
       TU77	     1600      2075	38912
       TU78	     1600      2075	38912
       TU80	     1600      2075	38912
       TU81	     1600      2075	38912
       TU81E	     1600      2075	38912
       TZ05	     1600      2075	38912
       TZ07	     1600      2075	38912
       TZ30	     6667      1182	92416
       TZ85	     42500     4925	2453299
       TZ857	     42500     4925	2453299
       TZK08	     54000     3276	2073600
       TZK10	     16000     2580	483840

   2.  The rdump command starts	the remote server /usr/sbin/rmt	on the client
       machine to access the storage medium.  If the rdump command cannot
       find /usr/sbin/rmt, it will try /etc/rmt	and rmt.

   3.  The rdump program can detect remote tape	support	on Tru64 UNIX and
       ULTRIX systems.	However, due to	the lack of a standard for UNIX	mag-
       netic tape functions, it	cannot utilize remote tape support on other
       systems.	This means that	multivolume dumpsets can only be created when
       the remote system is Tru64 UNIX,	DEC OSF/1 (the former name of Tru64
       UNIX), or ULTRIX, or if there is	embedded multivolume support in	the
       remote system (such as is the case with VMS, where support is in	the
       Magtape ACP).  For rare cases where the remote system is	non-UNIX,
       compatibility may require that rdump not	use UNIX-like commands.	 In
       order to	obtain this behavior, the user or system manager should	use
       the following command:

       setenv OSF_RDUMP_SIMP_RCMD

       The previous command can	be used	on a system wide (global) or per
       rdump command basis.

   4.  For proper operation, the server's /.rhosts file	must contain the name
       or reference designation	of the client's	machine.

   5.  The rdump and the dump commands do not handle MFS or AdvFS filesys-
       tems.

   6.  After encountering tape write errors, dump or rdump queries the opera-
       tor about performing a rewrite.	If the operator	requests a rewrite, a
       rewind is performed, followed by	an attempt to rewrite the data.	In
       the event the no-rewind device is used, the user	should always load a
       new tape	to avoid the possibility of overwriting	previously written
       archives.







EXIT STATUS

  The dump and rdump commands exit with	0 status on success. Startup errors
  are indicated	with an	exit code of 1;	abnormal termination is	indicated
  with an exit code of 3.

EXAMPLES

   1.  To perform a full level 0 dump, enter a command similar to the follow-
       ing:
	    dump -0un -f /dev/tape/tape1_d0 -b 32 /fs1

       In this example,	0 specifies that all files in the file system fs1
       will be dumped to /dev/tape/tape1_d0; u specifies dump to update	the
       /etc/dumpdates file after a successful dump of the file system; and n
       specifies that operators	will be	notified.  The estimate	calculation
       will be based upon the tape device defaults.  The write block size is
       set to 32 kilobytes.

   2.  To dump a local file system to a	remote storage tape, enter a command
       similar to the following:
	    rdump -3u -f tape_server:/dev/tape/tape1_d0	/fs1

       In this example,	3 specifies the	dump level of all files	in the file
       system /fs1 that	will be	dumped to tape /dev/tape/tape1_d0 on system
       tape_server, and	u specifies the	dump to	update the /etc/dumpdates
       file after a successful dump of the file	system.	 The estimated calcu-
       lation will be based on the rdump defaults.  The	write block size will
       be the default.

   3.  To obtain an estimated number of	blocks and volumes for the current
       dump session, enter the following:
	    dump -0Ef /dev/tape/tape1_d0 /usr

       The system displays output similar to the following:
	    358696 blocks, 0.19	volumes

   4.  The following examples show alternative ways of scheduling backups.
       Select the backup schedule that best fits your needs.

	a.  7-day incremental schedule

	    The	following schedule is a	7-day incremental schedule.  This
	    schedule is	useful for small-to-medium storage systems.  The
	    basic algorithm is n, n+1, ...  The	number of dump files to	per-
	    form a full	restore	can vary from 1	to 7.  The following is	an
	    example of a 28-day	schedule:
		 0  1  2  3  4	5  6
			 0  1  2  3  4	5  6
			 0  1  2  3  4	5  6
			 0  1  2  3  4	5  6

	b.  7-day alternative differential schedule

	    The	following schedule is a	7-day alternative differential
	    schedule.  This schedule is	useful for small-to-medium storage
	    systems.  The basic	algorithm is n-1, n+3, ...  The	number of
	    dump files to perform a full restore can vary from 1 to 4.	The
	    following is an example of a 28-day	schedule:
			 0  5  4  7  6	9  8
			 0  5  4  7  6	9  8
			 0  5  4  7  6	9  8
			 0  5  4  7  6	9  8

	c.  28-day alternative differential schedule

	    The	following schedule is a	28-day alternative differential
	    schedule.  This schedule is	useful for small-to-large storage
	    systems.  The algorithm combines the 7-day incremental and the
	    7-day alternative differential schedules.  The number of dump
	    files to perform a full restore can	vary from 1 to 7.  The fol-
	    lowing is an example of a 28-day schedule:
			 0  5  4  7  6	9  8
			 1  5  4  7  6	9  8
			 2  5  4  7  6	9  8
			 3  5  4  7  6	9  8

	    This schedule limits full dumps to once a month.  Therefore, it
	    is possible	to lose	a month's worth	of data.  Alternative
	    approaches to address this problem might include duplicating the
	    full tape or doing full backups twice a month instead of once a
	    month.

FILES

  /sbin/dump
      The dump command path in single user mode.

  /usr/sbin/dump
      The dump command path in multiuser mode.

  /usr/sbin/rmt
      Used by the rdump	remote tape access program.

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

SEE ALSO

  Commands: restore(8),	rrestore(8), rmt(8)

  Files: acl(4), proplist(4)