just an update for those interested:

failed over SQL instance to passive node and up the SQL Max_server_memory to 36GB - showing less deadlocking and the WEB UI is responding quicker than I have seen it lately

So While i am trying to sort out the queries (table scans and deadlocking) we have some breathing space. Have more information.

1) this is a virtual cluster

2) HBA set to default - have asked for this to be increased

3) have VOIP on the same subnet as data

4) 1GB iSCSI SAN - don't know how the luns are made up likely to be RAID6 with high IOPS

Question: regardless of the RAID level if the IOPS are high would this be better than having a mixture of RAID 1 and RAID 5 on fast SAS disks?

thanks