iscsi configuration

Hi,

I've found some posts with tips for some iscsi config tweaks in the older v6 Beta threads.

We're also using DSS as storage for a vSphere setup and I'd like to get the best possible performace so is it recommended to change the iscsi settings from the default values?
Another question is do I need to change the config on both sides? DSS and ESXi?


I've found the following values:

maxRecvDataSegmentLen=262144
MaxBurstLength=16776192
Maxxmitdatasegment=262144
maxoutstandingr2t=8
InitialR2T=No
ImmediateData=Yes

I've also found the an answer which says that changing the MaxBurstLength results in problems:

Quote:

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Originally Posted by jsinclair

Todd -
I tried these settings again on my V6 beta SAN's, and once again all ESX servers (3.5 and 4) couldn't reconnect. I then tried to set them one at a time to see which setting caused the problem, and it's the MaxBurstLength setting. Every other setting allows the initiators to reconnect.

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Best regards
Marc

I have DSS v5 connected to ESX 4 (vSphere) and I have those settings applied to my environment.

I seem to get errors only when I enable Write-Back Caching on the individual LUNs on each target.

I get some nasty errors in the VMKernel logs that point to storage going OFFLINE and ONLINE and a bunch of 'abort task' commands are issued.

I wonder what the deal is with the WB Cache and VMWare. Maybe they just don't like eachother.

Hey Parkplace

could you show us some of the errors that you received when you enabled Write-Back Caching on the individual LUNs on each target.

I am getting some and want to compare

Thanks

Here is my vmkernel log.

vmkernel.2

The errors start in the log at: Jul 13 03:14:30

All the other messages you see before and after are what I get every 5 minutes.

-Drew