I have been having issues w/DAVG being above 10. In fact, it is has been between 15-25. This is even after replacing my controller w/one w/1GB cache. I also upgraded the firmware for my drives. Here is the thing....even if I power down all my VMs (I only have 3), the DAVG is still between 15-25. What could be writing to my disk is all my VMs are powered down?
Lets get to ESXTOP to understand disk performance metrics, not getting into brief but a small overview of it: Below are 2 main counters of Storage performance which can be viwed with the help of esxtop:
DAVG: Indicates the latency at device driver end, it’s basically the time taken by I/O request to HBA driver from storage driver. It is the good indicator of performance of backend storage. Min Latency should be 25 or lower than it, of its higher than 25 then the latency is caused by your storage array, FC Switch misconfiguration or faults.
DAVG is not disk utilized by your VMs, infact disk performance varies from OS to OS in windows you can try using perfmon\Physical Disk counters to monitor disk performance. In your case i think its normal .
KAVG: Min threshold value of this counter should be between 0-2, if it’s higher than 2 it indicates the disk I/O latency from host kernel storage stack. Disk I/Os could be queued at kernel level if it’s high. This can seriousy impact your VMs performance.