reading past EOT marks

[Hyman Wong]

Hello out there in UNIX-land!  I need some assistance in the usage of
tapes.  Specifically, I'm trying to do dumps of disks to a tape, except
I want to use the tape for more than one dump.  I'm trying to keep an
index of all the files dumped so far as the first file on tape, which
will be used for restoring any files.  The index is pre-allocated on the
tape to about 1mb.  When I go to use the tape again for another backup,
I read in the index, position the tape to the last record, and dump
files, adding the filenames and other useful info to the index.  Then
when the dump is done, I rewind the tape and rewrite the index to the
allocated space at the beginning of the tape.

Now here's the problem, after rewinding the tape and writing out the
index, I get two End-Of-Tape markers after it, to signal the end of the
tape.  Here's what it looks like:

file 1, EOT, EOT, file 2, EOT, file 3, EOT, EOT
        ~~~~~~~~Yikes!  

The problem is that I can't seem to read past the first pair of EOT
markers, no matter what I try.  Is there a way of doing it with mt, dd,
or tar?  Anyone know of a another way to read past the End-Of-Tape
marker pairs?

Any suggestions, comments or advice is greatly appreciated.

-------------
Hyman Wong  (hyman at ria.ccs.uwo.ca)
Computing and Communications Services
The University of Western Ontario