This isn't strictly related to Amanda but this list has been an
excellent resource for tape drive configuration in the past, so I am
hoping someone here can help.
I've recently obtained an LTO4 drive to upgrade my Amanda backup
infrastructure. I've installed it into our changer and all the basic
tests check out, and now I am trying to adjust the block size for
performance. I'm testing options by writing 10GB files to the tape
using dd and tar with various block sizes. It seems I am hitting a
limit of 512k on my block size - any more and I get "device or resource
busy" errors from the dd and tar commands.
I am thinking I might have some sort of OS limitation. My OS is CentOS
5 and my kernel on the tape server at the moment is 2.6.18-53.el5PAE.
Does this sound familiar to anyone?
Any other causes of this? I was wondering if this was somehow a
parameter of the tape drive but using block sizes of 1MB and 2MB seems
very common for LTO-4 tape drives.
Appreciate any thoughts you all might have. It's working perfectly with
512k blocks, but performance is at about 63MB/sec and I think I should
be able to get some more out of the drive.
Thanks,
Fran
--
Fran Fabrizio, Senior Systems Analyst
Department of Computer and Information Sciences
University of Alabama at Birmingham
http://www.cis.uab.edu/ | 205.934.0653
