# 2.11BSD#431 - /usr/man/cat8/dump.0

    DUMP(8)             UNIX Programmer's Manual		  DUMP(8)

    NAME
         dump - incremental file system dump

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

    DESCRIPTION
         Dump copies to magnetic tape all files changed after a cer-
         tain 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 cartridge 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
    	  backups 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 read-
    	  able 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

    Printed 11/26/99						1

    DUMP(8)             UNIX Programmer's Manual		  DUMP(8)

    	  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 determined 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 something 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.

    Printed 11/26/99						2

    DUMP(8)             UNIX Programmer's Manual		  DUMP(8)

         Dump tells the operator what is going on at periodic inter-
         vals, 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 control-
         ling 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 sys-
         tem 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
         operator running restor.

    Printed 11/26/99						3

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