We have a slightly strange performance issue with some of our vm's, which appears linked to specific hosts.
We have 7 hosts. There are 7 vm's running the same share of the same workload, 1 on each host, the vm's running on 2 of the hosts show some differences;
- within the guest os load average and cpu usage are far higher than shown within vCenter (for the other vm's it matches up).
- slower transaction response times.
- ready time is under 1% (generally lower than on the other vm's).
- lower cpu usage within vCenter than the other vm's.
- if we swap the vm's round, whichever 2 end on these hosts start exhibiting the same behaviour.
- the 2 hosts are not over loaded, if anything they have lower cpu usage than the other hosts (all generally around 40%), though we do have a virtual/physical cpu ratio of about 3-1.
We are running lots of other vm's, some show minor signs of the same behaviour but it's a specific workload (which uses a lot of cpu) that is being affected the most.
All our hosts are running the same ESXi build which (along with vCenter) are the latest bar 1 patch levels.
There is some variety of hardware, but we have 2 other hosts that are exactly the same not showing this behaviour.
I've run out of ideas. Anyone have any suggestions as to what could be causing this.
