Reading an unknown DAT Tape

Martin McCormick martin at dc.cis.okstate.edu
Thu Mar 15 20:39:42 UTC 2012


	This is a case of idle curiosity and not an urgent need
to recover a valuable backup. I found an old DAT tape and
attempted to read it on the very drive that probably once wrote
it and it appears to read the tape properly in that I can use dd
to copy it to a file and mt fsf 5, for example, takes the tape
to the fifth file marker so there is sanity.

	Tar, however, does not recognize the format of the
archive so it is either something proprietary or I am not using
the correct utility on it.

	I opened it with dd files=2 if=/dev/sa0 of=testfile and
then did the strings utility on testfile and got:

TAPE
SSET
VOLB
DIRB
NACL
Setting security
iles
SPAD
DIRB
NACL
Setting security on system files...
SPAD
DIRB
NACL
SPAD
DIRB
NACL
SPAD
FILE
NACL
STAN
Jun 23 2003 12:00AM
Jan 1 1900  8:45AM
Jan 1 1900  9:00AM

	Note that we are obviously able to read data from the
tape as the top few lines are readible as words. The time stamps
at the bottom are possibly not time stamps as some of them are
not plausible.

	The dd command never faltered with errors although I
did finally stop it manually.

	Is there any FreeBSD utility that can tell more about
what created the original archive?

	Thank you.

Martin McCormick


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