We have 24 hosts, six Equallogic iSCSI arrays with 2 - 4 ports from each host connected to the Equallogic's via 2 x 3750's. From time to time I see sluggish performance on vm's that appear to be disk related, slow load times, long pauses between opening programs, slow load on some applications, etc when the CPU and memory is very low.. If I check the volumes on the SAN side using SANHQ the latency does not appear to be the cause, likewise the performance, latency or throughput in vcenter does not show anything immediately evident.
I am trying to understand how I could determine if adding more NIC's for my iscsi SAN would improve performance or not. What metric/s should I be looking at to determine whether two nic's are causing a performance bottlneck for IO or if the problem lies somewhere else?
