On Fri, 16 Dec 2005 at 9:22am, Roy Heimbach wrote
We have amanda 2.4.5p1 server running under debian linux on a dual opteron that's driving a new overland tape library with an ultrium3 drive. For now, the holding disk is a dedicated local 120 GB drive.
A single drive is going to have an awfully hard time... scratch that. A single drive can *not* feed an lto3 drive as fast as it wants to be fed (even if that's the only thing it's trying to do). I've got a 4 disk hardware RAID0 feeding my lto3 drive.
There's an amanda 2.4.5p1 client also running under debian linux on another dual opteron that's connected to the amanda server host via a dedicated gig network. This host is a moderately loaded fileserver with hardware raid. Backing up a 10 GB test partition, we're seeing dumper and taper performance around 2.5 MB/sec, a fraction of what the hardware is capable of.
*snip*
Any suggestions would be welcome.
Priority one is to figure out where the slowdown is. Bench the hardware RAID with something like bonnie++ and/or tiobench. Ditto for the holding disk. Use tar to write /dev/zero (using your chosen blocksize) to the tape drive. Then, do a test amdump to holding disk. Amflush that dump.
-- Joshua Baker-LePain Department of Biomedical Engineering Duke University