[lug] DDS-4 tape issue

George Sexton gsexton at mhsoftware.com
Tue Mar 9 16:41:28 MST 2004


I was looking at mt this weekend, and it looks like the mt suse ships is
the one from the GNU CPIO package, and it's pretty old and lacking
functionality (at least compared to the one shipped with RH 7.2). In my
particular instance I found that the "load" or "online" isn't supported.
Additionally, RH 7.2's mt supported a compression on/off ioctl that the
one with SUSE 9.0 doesn't.

My thinking is to find where RedHat's MT is from and use it instead of
the one that SUSE ships.

-----Original Message-----
From: lug-bounces at lug.boulder.co.us
[mailto:lug-bounces at lug.boulder.co.us] On Behalf Of Gary Hodges
Sent: Tuesday, March 09, 2004 4:28 PM
To: Boulder (Colorado) Linux Users Group -- General Mailing List
Subject: [lug] DDS-4 tape issue


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

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