On Tue, Jul 08, 2003 at 03:23:14PM -0700, David S. Miller wrote:
> dbench type stuff,

realizing dbench is blissfully ignorant of the system (2GB RAM),
for grins I ran "dbench 500" to see what would happen. The throughput
rate dbench reported continued to decline to ~20MB/s. This is about what
I would expect for one disk a 40MB/s SCSI bus.

Then dbench started spewing errors:
...
(7) ERROR: handle 13781 was not found
(6) open clients/client428 failed for handle 13781 (No such file or
directory)
(7) ERROR: handle 13781 was not found
(6) open clients/client423 failed for handle 13781 (No such file or directory)
(7) ERROR: handle 13781 was not found
(6) open clients/client48 failed for handle 13781 (No such file or directory)
(7) ERROR: handle 13781 was not found
(6) open clients/client55 failed for handle 13781 (No such file or directory)
(7) ERROR: handle 13781 was not found
(6) open clients/client419 failed for handle 13781 (No such file or directory)
(7) ERROR: handle 13781 was not found
(6) open clients/client415 failed for handle 13781 (No such file or directory)
...
write failed on handle 13783
write failed on handle 13707
write failed on handle 13808
write failed on handle 13117
write failed on handle 13850
write failed on handle 14000
write failed on handle 13767
write failed on handle 13787
...

NFC what that's all about. sorry - I have to punt on digging deeper.
I really need more guidance on
	(a) how much memory I should be testing with
	(b) how many spindles would be useful (I've got ~15 on each box)
	(c) how to tell dbench to use the FS mounted on the target disks.

I've attached the iommu stats in case anyone finds that useful.

grant