[ofa-general] WinOF_2_0_5/SRP initiator: slow reads and eventually hangs

[Bart Van Assche]

On Tue, Aug 11, 2009 at 11:52 PM, Chris Worley<worleys at gmail.com> wrote:
> I setup my target exactly as you prescribe... but my initiator is
> still Windows (version of WInOF at top): performance as relayed by
> IOMeter starts high and the average slowly decreases.  Watching the
> instantaneous throughput, there seem to be longer and longer lags of
> poor performance. between moments of good performance.  I need to run
> this against a Linux initiator to see if the problems are w/ WinOF.
>
> Using OFED 1.4.1 (w/ the stock RHEL kernel) on the target, the
> performance was steady and getting close to acceptable.  In a 15 hour
> test that cycles through sequential and random LBA's and R/W mixes
> from block sizes from 1MB to 512B, it worked well and got decent
> performance until it hit 1KB sequential reads which hung IOMeter; no
> messages on the Linux side (all looked okay).  IBSRP on the Windows
> side just said "a reset to device was issued" every 15 to 30 seconds
> after the problem started. I reloaded the IB stack on the Linux side,
> and was able to get it restarted.
>
> Still a lot of combinations to test.

Which trace settings are you using on the target ? Enabling the proper
trace settings via /proc/scsi_tgt/trace_level might reveal whether you
are e.g. hitting the QUEUE_FULL condition. See also scst/README.

Bart.