[lug] DDS-4 tape issue

[Gary Hodges]

Seagate Scorpion DDS-4
SuSE v9.0 Pro

I've just discovered a drive capacity issue.  I was backing up about 11 
GB of data with a used tape (erased) using hardware compression and the 
tape filled up.  I should be able to write 20 GB uncompressed and 40 
compressed. 

space:~ # mt -f /dev/nst0 stat
drive type = Generic SCSI-2 tape
drive status = 637534720
sense key error = 0
residue count = 0
file number = 0
block number = 0
Tape block size 512 bytes. Density code 0x26 (unknown).
Soft error count since last status=0
General status bits on (41010000):
 BOT ONLINE IM_REP_EN

I'm thinking this must be an issue with the density code 0x26.  If I run 
the following (some results edited out):

space:~ # mt -f /dev/nst0 densities
0x17   MFM 42500 bpi
0x24   DDS-2
0x8c   EXB-8505 compressed

there is no 0x26 listed.  Just a guess on my part, but I suspect SuSE 
must be defaulting to a lower capacity.  I've done some google 
searching, but there isn't much turning up.  I did see a suggestion to 
tell tar that the tape is really long so it doesn't guess when it is 
running out, but there must be a better way.

Gary