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BSD 2.11 - man page for dump (bsd section 8)

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DUMP(8) 										  DUMP(8)

NAME
       dump - incremental file system dump

SYNOPSIS
       dump [0123456789BchfusTdWwn [argument ...]] [filesystem]

DESCRIPTION
       Dump copies to magnetic tape all files changed after a certain date in the filesystem.

       The following options are supported by dump:

       0-9  This  number  is  the `dump level'.  All files modified since the last date stored in
	    the file /etc/dumpdates for the same filesystem at lesser levels will be dumped.   If
	    no date is determined by the level, the beginning of time is assumed; thus the option
	    0 causes the entire filesystem to be dumped.

       B records
	    The number of dump records per volume.  This option overrides the calculation of tape
	    size based on length and density.

       c    This  option  requires  no	further options.  Used to specify that the tape is a car-
	    tridge drive rather than a 9-track.

       h level
	    Honor the user 'nodump' flags only for dumps  at  or  above  the  given  level.   The
	    default  honor level is 1, so that incremental backups omit such files but full back-
	    ups retain them.

       f    Place the dump on the next argument file instead of the tape.  If '-' is  given  then
	    standard out (stdout) is written to.

       u    If	the  dump  completes successfully, write the date of the beginning of the dump on
	    file /etc/dumpdates.  This file records a separate date for each filesystem and  each
	    dump  level.   The	format of /etc/dumpdates is readable by people, consisting of one
	    free format record per line: filesystem name, increment  level  and  ctime(3)  format
	    dump  date.   /etc/dumpdates may be edited to change any of the fields, if necessary.
	    Note that /etc/dumpdates is in a format different from that which  previous  versions
	    of dump maintained in /etc/ddate, although the information content is identical.

       s    The size of the dump tape is specified in feet.  The number of feet is taken from the
	    next argument.  When the specified size is reached, dump will wait for  reels  to  be
	    changed.  The default tape size is 2300 feet.

       d    The  density of the tape, expressed in BPI, is taken from the next argument.  This is
	    used in calculating the amount of tape used per reel. The default is 1600.

       T date
	    Use the specified date as the starting time for the dump instead of the  time  deter-
	    mined  from  looking  in  /etc/dumpdates.	The format of date is the same as that of
	    ctime(3).  This option is useful for automated dump scripts that wish to dump over	a
	    specific period of time.  The T option is mutually exclusive with the u option.

       W    Dump  tells  the  operator	what file systems need to be dumped.  This information is
	    gleaned from the files /etc/dumpdates and /etc/fstab.  The W option  causes  dump  to
	    print  out,  for  each  file  system  in /etc/dumpdates the most recent dump date and
	    level, and highlights those file systems that should be dumped.  If the W  option  is
	    set, all other options are ignored, and dump exits immediately.

       w    Is like W, but prints only those filesystems which need to be dumped.

       n    Whenever  dump  requires operator attention, notify by means similar to a wall(1) all
	    of the operators in the group "operator".

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

       Dump  requires  operator  intervention on these conditions: end of tape, end of dump, tape
       write error, tape open error or disk read error (if there are more  than  a  threshold  of
       32).   In addition to alerting all operators implied by the n key, dump interacts with the
       operator on dump's control terminal at times when dump can no longer proceed, or if  some-
       thing  is  grossly  wrong.   All  questions dump poses must be answered by typing "yes" or
       "no", appropriately.

       Since making a dump involves a lot of time and effort for  full	dumps,	dump  checkpoints
       itself  at  the	start of each tape volume.  If writing that volume fails for some reason,
       dump will, with operator permission, restart itself from the checkpoint after the old tape
       has been rewound and removed, and a new tape has been mounted.

       Dump  tells  the  operator  what  is going on at periodic intervals, including usually 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 dump is busy, and will be for some time.

       Now a short suggestion on how to perform dumps.	Start with a full level 0 dump

	    dump 0un

       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 is taken on a set of fresh tapes that is saved forever.

FILES
       /dev/rxp0a      default filesystem to dump from
       /dev/rmt0       default tape unit to dump to
       /etc/ddate      old format dump date record (obsolete after -J option)
       /etc/dumpdates  new format dump date record
       /etc/fstab      Dump table: file systems and frequency
       /etc/group      to find group operator

SEE ALSO
       restor(8), rdump(8), dump(5), fstab(5), dumpdir(8)

DIAGNOSTICS
       Many, and verbose.

BUGS
       Sizes are based on 1600 BPI blocked tape; the  raw  magtape  device  has  to  be  used  to
       approach  these densities.  Fewer than 32 read errors on the filesystem are ignored.  Each
       reel requires a new process, so parent processes  for  reels  already  written  just  hang
       around until the entire tape is written.

       It  would  be nice if dump knew about the dump sequence, kept track of the tapes scribbled
       on, told the operator which tape to mount when, and provided more assistance for the oper-
       ator running restor.

4th Berkeley Distribution								  DUMP(8)
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