2 hosts with HA enabled/Adm control disabled

[tdubb123]

I got numerous 2 host clusters with HA enabled but adm control disabled

If I enabled adm control and set the failover host to 1, how do I know if the other host can accomodate all VMs?

Is there a formula to calculate this?

or does it make sense to set it at 25% capacity? I think I will need 1 full host capacity failover incase one host fails, all vms can be restarted on the other. but I am not sure the memory on the other host can take it

[DavoudTeimouri]

Hi,

As you may know, when admission control is disabled, it's allowing host to run virtual machines without considering about fail-over capacity and it's not recommended except test cases.

Also about HA resource calculation, you should consider about HA slot and you need to prepare a "Capacity Plan" for your environment but as a standard configuration, you need to N+1 hosts in each cluster.

You can find some calculator in the below links and also more information about calculation:

http://www.vmwarearena.com/ha-slots-calculation/

https://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=10105...

http://www.joshodgers.com/vsphere-cluster-sizing-calculator/

http://thinkingloudoncloud.com/calculator/vmware-ha-admission-control-calculator/

http://blogs.vmware.com/vsphere/2012/06/vsphere-ha-admission-control-calculation-for-memory.html