Below is Kernel disk latency and physical device command latency.
Kernel disk latency: Is the amount of the time vmkernel took to process SCSI command, which is kind of queue on
vmkernel side as it has got lot of stuff to process.ideal counter is 0-1 millisecond
Physical device command latency: it is amount of time taken by physical device to complete scsi, here physical device start from HBA, Storage switch and till it reaches storage port. Ideal counter is 15 millisecond.
If you see above, both the counters are showing average value more than ideal value. It is all because the way I configured my system.