[Beowulf] Re: [OT: LTO Ultrium (3) throughput?
landman at scalableinformatics.com
Wed Jun 18 21:09:30 EDT 2008
David Mathog wrote:
> Joe Landman wrote:
> Maybe it will mean more to you than it does to me...
> % lsscsi --long
> [8:0:0:0] tape HP Ultrium 3-SCSI D21D /dev/st0
> state=running queue_depth=32 scsi_level=4 type=1 device_blocked=0
Hmmm... queue_depth of 32? On a tape? Weird. There has been some
strangeness in the TCQ/NCQ layers. Might want to try to set this to 1
and see if it helps
echo 1 > /sys/block/st0/device/queue_depth
(note: some drivers don't support changing the queue_depth)
> lspci -v
> 04:04.0 SCSI storage controller: Adaptec ASC-29320ALP U320 (rev 10)
> Subsystem: Adaptec ASC-29320LPE PCIe U320
> Flags: bus master, 66MHz, slow devsel, latency 32, IRQ 19
> I/O ports at 4400 [disabled] [size=256]
> Memory at d8400000 (64-bit, non-prefetchable) [size=8K]
> I/O ports at 4000 [disabled] [size=256]
> [virtual] Expansion ROM at d8600000 [disabled] [size=512K]
> Capabilities: [dc] Power Management version 2
> Capabilities: [a0] Message Signalled Interrupts: Mask- 64bit+ Queue=0/1
> Capabilities:  PCI-X non-bridge device
Looks like a PCI-x adapter. This shouldn't be an issue though.
Try changing the block size. 2M to 8M, and see what happens.
Joseph Landman, Ph.D
Founder and CEO
Scalable Informatics LLC,
email: landman at scalableinformatics.com
web : http://www.scalableinformatics.com
phone: +1 734 786 8423
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