We have a Windows 2012 R2 server that has become slugggish. If I ping the server it will be 1ms and then after around 10-20 seconds 100-250ms for about 10seconds. All other Vms on the same subnet and host are all fine. The CPU and memory utilisation are low and it has lots of free space. The network is around 2mbps each way.
Is it disk activity, how can tell?
I'm not too experience in the performace area of VMs in vCenter.
if you have already done the usual checks, i.e. VMtools, HW version and VMXnet3 adapter, then use esxtop to find out where the bottleneck is.
Duncan Epping has got a brilliant write up on esxtop along with threshold values. ESXTOP - Yellow Bricks