VSphere High Disk Latency on VMs

[techie08]

Hi Everyone

 

Every so often, possibly a couple of times a week, i get high disk latency errors on some VMs. Would this indicate a problem with the SAN storage or the ESX hosts? When this happens we get a drastic slowdown of the network and it may last for about 10 mins or so.

 

Many Thanks

[mrbios]

Quite a large variety of things that could be causing it. Is your storage running close to capacity in terms of performance? Is it happening at a consistent time of day and/or day of the week?

 

Best bet would be to start with the performance graphs and see if any particular VMs are causing it. What type of connectivity are you using between hosts and SAN? if it's iSCSI check switch logs too, there's always a possibility a drive is failing in the SAN and it hasn't picked up on that yet (depends on how good the SAN is at picking that sort of thing up mind you)

 

Probably something else in the mix i haven't listed, but good luck

[techie08]

Is there a way i can find out who is doing excessive file copying on the network as i think this could the contributing factor in our network slowness.