Hello
You might try turning off hardware compression at the drive and see if they
improves things. The data may be growing on the second compression pass.
Also what is the block size you are using to write the data to tape. You have
an inter-record gap between each block. The smaller the block size, the greater
the number of inter-record gaps.
len
-----Original Message-----
From: veritas-bu-admin AT mailman.eng.auburn DOT edu
[mailto:veritas-bu-admin AT mailman.eng.auburn DOT edu]On Behalf Of Mathieu
Nantel
Sent: Wednesday, June 16, 2004 1:15 PM
To: veritas-bu AT mailman.eng.auburn DOT edu
Subject: [Veritas-bu] SDLT320 : ?REAL? native capacity
Good day (again),
I've recently been archiving pre-compressed data in bz2 format to tape. I'm
quite certain that my SDLT drive's hardware compression is not as good as
bz2, so there probably isn't too much compression going on.
The reason I'm saying this is that I was able to fit a mere 142 gigs on a tape
which is meant to have a NATIVE capacity of 160 gigs.
This rose a few questions here. Is this analoguous to the way hard drive
vendors count hard drive space in base 10 vs base 2 for computers? In this
case, I shouldn't be loosing any more than 2.4% of the space (1000KB vs
1024KB). (142*100/160) tells me that I've got a 11.75% loss of space, which
sounds a bit too much to me.
Anyone can shed some light on this?
Thanks,
--
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Mathieu Nantel - RHCE,BOFH Ecopia BioSciences
Systems Manager (514) 336-2724 x434
nantel AT ecopiabio DOT com
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