Virtual disk performance read/write latency

[zenomorph]

Hi there,

I'd like some assistance on interpreting the vCentre "virtual disk" statistics. Were running a faily busy SQL server VM and based on best practice the "avg disk sec/transfer" figures should be between 10 - 30ms or the latency of disk read/wrtie.

Now if I'm monitoring the stats from vCentre "vritual disk" it shows the read/write latency for:

scsi0:1

scsi0:2

scsi0:3

can anyone advise how I should interpret these or what figure I should expect the charts is showing between 4 - 40ms for transfer/read latency?

Many thanks......

[mcowger]

Those are the right statistics to look at - each one of those is a disk within your VM.  4ms is pretty good, 40 not so much.  Take a look at your average over time - if you are averaing over ~10ms, you will start to see some performance impact in the VM.

[Dotcomm]

What about a write latency of 130325887...?

That's what I'm getting just before midnight. All the numbers around it are mostly single digits, all below 16, and the highest other one is 30.

Is there a known midnight VMware latency bug?

[Dotcomm]

SCSI generally attaches to a drive nowadays, so I would look at something you have three of. I have 3 also, and we have three ESXi servers, so I'm guessing that it's the response time to each ESXi server.