DAT tape block sizes

[Derek Seaman]

This isn't an AIC7xxx specific question, though my Linux machines are using
the AIC driver. Our department produces Sybase 11 database tapes (4mm DATS)
which use variable block size records. Trying to copy them with dd doesn't
work since dd expects fixed record lengths.

What I need to do is read the tape to the HD, and then write it back out to
another tape, while preserving the correct (and varying) block sizes. If
that fails, a direct tape to tape copy would be acceptable.

Is there any scsi tape program, besides dd, which will correctly handle such
tapes?

Also, I need a way to find out a 4mm DAT currently in the drive was written
with compression turned on or off. Note, I don't mean the current status of
the compression flag. I mean whether the data previously written on the tape
is compressed or not. The 'mt' status command does not reflect what was
written on the tape, but rather the current tape compression flag.

Thanks for any input!

Derek L. Seaman, Engineer
Tactical Cryptologic Systems, D7213
SPAWAR System Center, San Diego
dseaman at spawar.navy.mil
Ph: (619) 553-6795
Fx: (619) 553-1133


To Unsubscribe: send mail to majordomo at FreeBSD.org
with "unsubscribe freebsd-aic7xxx" in the body of the message