[Gllug] Tape drive compression

[Darren Beale]

Hi

I've just started using Seagate 10/20GB IDE Travan drive to back up my local
Debian server here. I've had the drive nearly 2 years now, but for some
reason this is the first time that I've ever used it <shrug>

Anyway, my question is how does one switch on data Compression?

If I do dmesg I notice that it says that it does not support data
compression (last line):

ide-tape: hdc <-> ht0: Seagate STT20000A rev 8A51
ide-tape: Dumping the results of the MODE SENSE packet command
ide-tape: Mode Parameter Header:
ide-tape: Mode Data Length - 23
ide-tape: Medium Type - 183
ide-tape: Device Specific Parameter - 16
ide-tape: Block Descriptor Length - 0
ide-tape: Capabilities and Mechanical Status Page:
ide-tape: Page code - 42
ide-tape: Page length - 18
ide-tape: Read only - No
ide-tape: Supports reverse space - Yes
ide-tape: Supports erase initiated formatting - No
ide-tape: Supports QFA two Partition format - Yes
ide-tape: Supports locking the medium - No
ide-tape: The volume is currently locked - No
ide-tape: The device defaults in the prevent state - No
ide-tape: Supports ejecting the medium - No
ide-tape: Supports error correction - Yes
ide-tape: Supports data compression - No

However the tapes I have are Travan NS 20GB Compatible, which are 10/20GB
uncompressed/compressed and I thought that the drive could handle this
http://rss.seagate.com/products/srssDrives/STT220000A-M.html (as I said, I
bought it a while back, but that looks like the same drive)

So how do I get 20GB out of this puppy? is it a dump option? I see dump -z
and dump -j (bzip)

Currently I run
dump -0u -a -f /dev/tape /dev/${device} >> /var/log/backup.log

I would appreciate some guidance here, thanks

--
Darren Beale - Acksys Ltd
Office: 020 8530 1454
Fax: 07092 394822
Mobile: 07711 716197
http://www.acksys.co.uk



-- 
Gllug mailing list  -  Gllug at linux.co.uk
http://list.ftech.net/mailman/listinfo/gllug