Tape throughput for Sony AIT-3

From: John Doe <john_at_doe.com>
Date: Wed, 2 Oct 2002 11:07:58 -0400
Message-ID: <anf251$dg8pu$1@ID-80970.news.dfncis.de>

I am trying to backup the database using Sony SDX-700C AIT-3 drive. When I test the drive speed with

dd if=/dev/zero of=/dev/rmt/0un bs=128k count=8192,

I get a throughput of 18MB/sec.

But when I 'tar' a Oracle datafile onto the tape, I get a pathetic throughput of 5MB/sec.

Why the drastic drop? I know Oracle datafile probably dont compress well, but I still expect to get the uncompressed spec'd rating for the drive which is 12MB/sec.

Any help appreciated.

Thanks Received on Wed Oct 02 2002 - 10:07:58 CDT