I have an IBM DS3524 Storage Subsystem connected with one fiber channel adapter to an IBM server with ESXi 5.0.
I am seeing some large numbers when I run esxtop. My DAV/CMD goes up to 168 or 90 every minute or so. Most of the time it is hovering around 14.75.
I am seeing in the logs:
cpu20:4116)NMP: nmp_ThrottleLogForDevice:2318: Cmd 0x28 (0x412440385100) to dev "naa.60080e50002364aa000002bc4eb181de" on path "vmhba5:C0:T0:L6" Failed: H:0x0 D:0x2 P:0x0 Valid sense data: 0x5 0x94 0x1.Act:FAILOVER
2013-09-05T13:49:11.778Z
cpu6:4102)WARNING: NMP: nmp_DeviceRetryCommand:133:Device "naa.60080e50002364aa000002b44eb14998": awaiting fast path state update for failover with I/O blocked. No prior reservation exists on the device.
2013-09-05T13:49:12.526Z cpu8:4282)WARNING: vmw_psp_fixed: psp_fixedSelectPathToActivateInt:464:Selected current STANDBY path vmhba5:C0:T0:L6 for device naa.60080e50002364aa000002bc4eb181de to activate. This may lead to path thrashing.
In Events I am seeing that I am losing connection to the storage device immediately followed by a reconnect.
I logged onto my storage device and noticed that the write cache is off. Could the write cache being off cause this level of IO issue?
Thanks,
Brian