[Beowulf] Re: [OT: LTO Ultrium (3) throughput?

[David Mathog]

Joe Landman wrote:

> Have you adjusted the block size up?  maybe try
> 
> dd if=/dev/zero of=/dev/nst0 bs=8M count=1000

The tape has a 64Mb on board buffer and somewhere in the manual it said
that it shouldn't matter.  But no, I have not tried that yet and will
do so tomorrow.

> This said, have you tried the "obvious" tests, such as what does lsscsi 
> report, and lscpi -v for that adapter, and ...

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
timeout=900

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
Enable-
	Capabilities: [94] PCI-X non-bridge device

/proc/interrupts shows that this controller is the only thing on
IRQ 19.

Thanks,

David Mathog
mathog at caltech.edu
Manager, Sequence Analysis Facility, Biology Division, Caltech