I've never been a fan of using VMs / Core. 2 VMs can be completely different hence this is a very rough calc. I'd suggest profiling the workloads that you want to run on the cluster using some...
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I've never been a fan of using VMs / Core. 2 VMs can be completely different hence this is a very rough calc. I'd suggest profiling the workloads that you want to run on the cluster using something like VMware Capacity Planner, Platespin Recon etc to measure the max cumulative peak MHzs. You’re not looking for avg CPU or the sum of the peak values for each worked (as they may peak at different times) but the cumulative highest value seen. Then use this as your upper limit plus say 10% as you're requirement. Then look at your hardware and work out how much CPH MHz is available then size on that. Much better than x vms/core. Still allow for N+1 As for values to measure I’d look at CPU Ready value on the VMs. This shows how long VMs have to wait to get CPU time and indicates CPU contention. Also if you’re using hyper threading on an Intel server then I’d considering increasing the following values, especially if you’re getting close to max and running a lot of VMs. http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1020233 I’d look to increase the HaltingIdleMsecPenaltyMax To 8000 and HaltingIdleMsecPenalty to 2000 Both are advanced settings on the host. Pete