dump -- Command

File-system backup utility
dump [options] [argument ...]

dump dumps either all or a portion of file system argument to magnetic tape
or floppy  disks.  File-system dumps  are in a  format that permits  you to
restore all or some of the files to the original file system, and to select
files either by name or by i-number.

A file-system  dump includes all  files changed since the  dump since date,
plus each file's full path name (for the benefit of dumpdir).

options specifies both the  dump-since date and the processing options.  It
is made  up of  characters from the  set 0123456789bdfsSuv, which  have the
following meanings.

0-9 The digit gives  the level number of the dump.   The dump-since date is
    the  most recent  date in  the  dump-date file  /etc/ddate that  is (1)
    associated with this  file system and (2) has a  level number less than
    the current  dump level.  For  example, if you request  a level-3 dump,
    dump will back up all files  not backed up since the last level-2 dump.
    A level-0 dump by definition backs up all files in the file system.

b   The next argument gives the output tape's blocking factor.          The
    blocking  factor is  the  number of  dumpdata structures  in each  tape
    block.  The default blocking factor is 20.

d   The next  argument gives the  density of the  output tape in  bytes per
    inch.  The default density is 1600 bytes per inch (bpi).  dump uses the
    density to compute the quantity of tape needed.

f   The next  argument gives  the path  name of the  output file.  If  no f
    option is given, /dev/dump is assumed.

s   The next  argument gives  the length  of the dump  tape in  feet.  dump
    keeps a  running total of the  quantity of tape it  has written, and it
    asks for  a new reel  if it appears that  the end of the  reel is near.
    The default length is 2,300 feet.

S   The next argument gives the size  of the dump output device, in blocks.
    This is used only if you are backing up the file system to floppy disks
    or streaming cartridge tape rather than to nine-track magnetic tape.

u   If the  dump completes without  error, update the  record of successful
    dumps kept in file /etc/ddate. There is an entry in this file for every
    file system and every dump level.

v   Inform the user of the `dump since' date and the length of tape used in
    feet.   The  length  is  useful  for  computing the  quantity  of  tape
    remaining if multiple dumps are written onto a single reel of tape.

If no level number is given, dump assumes the options 9u.

Files

/dev/dump -- Default dump device
/etc/ddate -- Dump date file

See Also

badscan,
commands,
dumpdate,
dumpdir,
restor

Diagnostics

Most errors  are fatal caused  by a table  overflowing, or a  read or write
error on the input or output device.

dump requires  that its  output be  written to disks  that are free  of bad
sectors.  If you  write a dump to a disk  with bad sectors, you will not be
able to restore files from that disk.

When formatting disks to be used with dump, use the command

    /etc/fdformat -v device

This forces fdformat to verify the  format.  It takes twice as long, but it
ensures that the disk is good at least at a first level of testing.  Reject
any disks that have any defects  -- or save them for use with COHERENT file
systems, which can map out bad sectors.

Notes

Please  note that  dump is  now  regarded as  being obsolete.   We strongly
encourage users to use cpio instead.

© 2012 by Stephen A. Ness