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

NAME
     dump - incremental file system dump

SYNTAX
     dump [ key [ argument ... ] filesystem ]

DESCRIPTION
     _D_u_m_p copies to magnetic tape all files changed after a cer-
     tain date in the _f_i_l_e_s_y_s_t_e_m. The _k_e_y specifies the date and
     other options about the dump.  _K_e_y consists of characters
     from the set 0123456789fusd.

     f    Place the dump on the next _a_r_g_u_m_e_n_t file instead of the
          tape.

     u    If the dump completes successfully, write the date of
          the beginning of the dump on file /_e_t_c/_d_d_a_t_e.  This
          file records a separate date for each file system and
          each dump level.

     0-9  This number is the `dump level'.  All files modified
          since the last date stored in the file /_e_t_c/_d_d_a_t_e for
          the same file system 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
          file system to be dumped.

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

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

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

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

          _d_u_m_p _0_u

     Next, periodic level 9 dumps should be made on an exponen-
     tial progression of tapes.  (Sometimes called Tower of Hanoi
     - 1 2 1 3 1 2 1 4 ...  tape 1 used every other time, tape 2
     used every fourth, tape 3 used every eighth, etc.):

          _d_u_m_p _9_u

Printed 8/2/83                                                  1

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

     When the level 9 incremental approaches a full tape (about
     78000 512-byte blocks at 1600 BPI blocked 20, or 39000 1-
     kilobyte blocks), a level 1 dump should be made:

          _d_u_m_p _1_u

     After this, the exponential series should progress as unin-
     terrupted.  These level 9 dumps are based on the level 1
     dump which is based on the level 0 full dump.  This progres-
     sion of levels of dump can be carried as far as desired.

FILES
     default file system and tape vary with installation.
     /etc/ddate          record dump dates of file system/level.

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

DIAGNOSTICS
     If the dump requires more than one tape, it will ask you to
     change tapes.  Reply with a newline when this has been done.

BUGS
     Sizes are based on 1600 BPI blocked tape.  The raw magtape
     device has to be used to approach these densities.  Read
     errors on the file system are ignored.  Write errors on the
     magtape are usually fatal.

Printed 8/2/83                                                  2