Wednesday, October 7, 2009

HS21 Blades, Qlogic 4052, IBM DS3300 as an iSCSI Target for VMware

"...Read performance was decent from the array, but write performance was terrible, maxing out at 10Mpbs throughput and insanely high latencies on long writes when the system was under load.  This led to some long P2V operations, poor guest performance, and some questions from the project sponsors on why I couldn’t make the environment sing..."

"Issue seems to be with the Nortel switch and the qla4052. When first initialize they are able to connect to the switch fine, but when the firmware is loaded, they will not negotiate with the Nortel switch if the port is set to auto. Once the firmware is loaded you will notice that the link is down on the switch.
All you need to do is on the switch set the port to 1000 full duplex instead of auto"

"The problem is not the Qlogic. It is the Nortel switch. I have to downgrade the firmware version to or older then everything works. Even IBM & Nortel, they can repeat the problem but no solution yet anyway. But again once you have everything working, who will change the firmware again."