Cluster Balance - Host Ram Differences

[rbmadison]

We have several hosts that ram has been upgraded in our cluster and the cluster doesnt seem to put more resouces on these hosts even though they have more available resources. Is there a way I can tweak the system resource allocation or some other settings to get DRS to use the hosts more efficently? It's not causing and issue but as we add memory or hosts I would be concerned it's not using the extra capacity effectively.

Thanks

[weinstein5]

Remember DRS does balance the number of VMs across hosts so if the VMs is receiving sufficient resources then they will not move - you will have to manually migrate the vms to even them out

[rbmadison]

Yep, that makes sense but I see host alarms because they are being slightly stressed and I see servers with more ram just hanging around with tons of free ram. I know it will do a vmotion if it needs to but I'd like to see if there is a way I can balance the cluster out more automatically. It seems the allocation method looks at the lowest common resource on server and basis DRS on that.

[weinstein5]

The one thing to check is the DRS Migration Threshold Level and make sure it is set to Aggressive - uf there are some VMs that are close that would move - but if the Alarms you are seeing are on host memory is low does not mean that the host is not able to deliver memory resources to the VM