Several tapetype definitions are available in example/amanda.conf.
They inform Amanda how much it is supposed to be able to store in a
tape (length), how much space is wasted at the end of a dump image
with the EOF mark (filemark) and how fast the tape unit is (speed).

The most inportant parameter is length, since Amanda may decide to
delay a backup if length is too small, but, if it is too large, Amanda
may end up leaving dumps in the holding disk or having to abort some
dump.

Filemark is important if you have many disks, particularly with small
incremental backups.  The space wasted by so many filemarks may add up
and considerably modify the available tape space.

The speed is currently unused.


If none of the sample tapetype entries match your needs, you may
search the mailing list archives or look up the on-line list of
tapetype entries.  Just follow the links from www.amanda.org.


Amanda provides a utility to calculate the size of a tape, to generate
a `tapetype' entry for your amanda.conf.  However, this utility is
neither built nor installed by default.  You can build it by entering
the tape-src directory in the build tree (after running configure) and
typing `make tapetype'.

As soon as it is built, run it, specifying the appropriate tape
device, but beware that it may take many hours to run.  Make sure you
do not use hardware compression, even if you plan to use hardware
compression in the future.  `tapetype' writes random data to tape, and
random data will expand instead of compressing, therefore you'll get
an estimate that's smaller than expected.

