Mike Christie wrote:
> Hannes Reinecke wrote:
>> Mike Christie wrote:
>>> Hannes Reinecke wrote:
>> [ .. ]
>>>> Fsck. You are correct.
>>> But you still might be hitting a problem where the target does not like 
>>> data-outs when it closed the window. Maybe they interpreted the RFC 
>>> differently. You should ask the HP target guys for more info.
>>> Also your patch might be working because I think it ends up throttling 
>>> the connection, so IO does not timeout because pipes are backed up (the 
>>> slow down from the throttling is one of the problems we hit with the 
>>> patch I did before which was pretty much the same as you posted).
>> I actually had quite good results with it, so it can't be too bad :-)
>> IE the test HPs running continued for over a day, whereas previously
>> it'd stall after some hours.
> Yeah, I saw the bz update too.
> I tested your patch out here localy just to double check that is works 
> like what we had before. With a istor target write throughput goes from 
> 50 MB/s to 15 MB/s. It eventually dies (ping timeout) because the window 
> is closed and it does not open until we finish sending the data-outs for 
> the currently running commands. So READs are just fine. We hit the 
> window closed check but we continue to make progress on the READs 
> because data-ins are processed like normal and the window opens back up 
> as commands are completed.
> So someone is doing something screwy. I am testing a EQL box locally now 
> and will try some others just to double check.

Hannes, could you test without your cmdsn patch, but then set things up 
so we do not have to send data-out pdus?

You want immediate data = Yes.

node.session.iscsi.ImmediateData = Yes
node.session.iscsi.FirstBurstLength = 131072

Then either send IOs that are smaller than 131072 or set the 
/sys/block/sdc/queue/max_hw_sectors to 128

For the target you would want
ImmediateData = Yes
FirstBurstLength = 131072
MaxRecvDataSegmentLength = 131072

I guess you would want to lower the initiator values to match what the 
target is going to ask for if you cannot modify the target.

I am seeing a problem here when having to send data-outs even when the 
window is open, throughput dies from 111 to .61 MB/s.

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