I have a three server Hyper-V 2012 cluster which points at LUNs based on an HP MSA P2000 G3 SAN for the virtual hard disk storage. I am experiencing speed issues and one thing that has been highlighted is latency in the read/write speed to and from the SAN. I spoke to HPE who checked the SAN for hardware faults and found nothing. However, to me the performance data over the last four days looks to be spiking well above the 10-20ms range deemed acceptable. I don't have anything to compare my charts to as a baseline was never taken.
This storage system has worked well in the past and there haven't been any recent changes. If anyone can provide me with any insight into this i'd be very grateful.
Many thanks,
Steve
Best Answer
This model of HP SAN array had a problem with the write cache modules failing. These are 4GB Compact Flash cards installed on the controller modules.
If this is sudden behavior, that may be worth a check.
I'd suggest controller failover, but need the details about what type of P2000 G3 array this is (iSCSI, SAS, FC) and how it's connected to your hosts.