DUMP(VIII)                  11/24/73                   DUMP(VIII)


     dump - incremental file system dump


     dump [ key [ arguments ] filesystem ]


     Dump makes an incremental file system dump on magtape of all

     files  changed  after  a  certain  date.   The  key argument

     specifies the date and other options about  the  dump.   Key

     consists of characters from the set abcfiu0hds.

     a     Normally  files  larger  than  1000  blocks  are   not

          incrementally dump; this flag forces them to be dumped.

     b     The next argument is taken to be the maximum  size  of

          the dump tape in blocks (see s).

     c     If the tape overflows, increment the last character of

          its name and continue on that drive.  (Normally it asks

          you to change tapes.)

     f     Place the dump on the next argument  file  instead  of

          the tape.

     i     the dump date is taken from  the  entry  in  the  file

          /etc/dtab  corresponding  to  the  last  time this file

          system was dumped with the -u option.

     u     the date  just  prior  to  this  dump  is  written  on

          /etc/dtab  upon  successful  completion  of  this dump.

          This file contains a date for every file system  dumped

          with this option.

     0     the dump date is taken  as  the  epoch  (beginning  of

          time).   Thus  this option causes an entire file system

          dump to be taken.

     h     the dump date is  some  number  of  hours  before  the

          current  date.   The  number of hours is taken from the

          next argument in arguments.

     d     the dump date  is  some  number  of  days  before  the

          current  date.   The  number  of days is taken from the

          next argument in arguments.

     s     the size of the dump tape is specified in  feet.   The

          number  of  feet  is  taken  from  the next argument in

          arguments.  It is assumed that  there  are  9  standard

          UNIX  records  per  foot.   When  the specified size is

          reached, the dump will wait for reels  to  be  changed.

          The default size is 2200 feet.

     If no arguments are given, the key is assumed to  be  i  and

     the file system is assumed to be /dev/rp0.

     Full dumps should be taken on quiet file systems as follows:

             dump 0u /dev/rp0

             ncheck /dev/rp0

     The ncheck will come in handy in case  it  is  necessary  to

     restore  individual files from this dump.  Incremental dumps

     should then be taken when desired by:


     When the incremental dumps get cumbersome,  a  new  complete

     dump  should  be  taken.   In  this  way, a restore requires

     loading of the  complete  dump  tape  and  only  the  latest

     incremental tape.


     If the dump requires more than one tape, it will ask you  to

     change  tapes.   Reply  with  a  new-line when this has been

     done.  If the first block on the new tape is  not  writable,

     e.g.  because you forgot the write ring, you get a chance to

     fix it.  Generally, however,  read  or  write  failures  are



     /dev/mt0        magtape

     /dev/rp0        default file system



     restor (VIII), ncheck (VIII), dump (V)