4.3BSD - /usr/man/cat8/dump.0

DUMP(8)                                                                DUMP(8)


NAME
       dump - incremental file system dump

SYNOPSIS
       /etc/dump [ key [ argument ... ] filesystem ]

DESCRIPTION
       Dump  copies to magnetic tape all files changed after a certain date in
       the filesystem.  The key specifies the date and other options about the
       dump.  Key consists of characters from the set 0123456789fusdWn.

       0-9  This  number  is  the  ‘dump level’.  All files modified since the
            last date stored in the file /etc/dumpdates for the same  filesys‐
            tem  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.

       f    Place  the dump on the next argument file instead of the tape.  If
            the name of the file is ‘‘-’’, dump writes to standard output.

       u    If the dump completes successfully, write the date of  the  begin‐
            ning of the dump on file /etc/dumpdates.  This file records a sep‐
            arate date for each filesystem and each dump level.  The format of
            /etc/dumpdates  is readable by people, consisting of one free for‐
            mat 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.

       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.

       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 imme‐
            diately.

       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.

       Dump tells the operator what is going on at periodic intervals, includ‐
       ing  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/rrp1g      default filesystem to dump from
       /dev/rmt8       default tape unit to dump to
       /etc/dumpdates  new format dump date record
       /etc/fstab      dump table: file systems and frequency
       /etc/group      to find group operator

SEE ALSO
       restore(8), dump(5), fstab(5)

DIAGNOSTICS
       Many, and verbose.

       Dump exits with zero status on success.  Startup errors  are  indicated
       with  an exit code of 1; abnormal termination is indicated with an exit
       code of 3.

BUGS
       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.

       Dump with the W or w options does  not  report  filesystems  that  have
       never been recorded in /etc/dumpdates, even if listed in /etc/fstab.

       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 restore.


4th Berkeley Distribution        May 23, 1986                          DUMP(8)