Vikramaditya_J
Enthusiast
Enthusiast

Need advice on HA cluster failover capacity calculation after one host fails

Hello Community,

Need advice:-

I have a 3 node HA cluster, with each host has 96 GB physical memory installed (Total cluster capacity is 288 GB) and out of that 33% memory (i.e., 95 GB) is reserved by HA for cluster fail-over.

Each host has 6 powered-on VMs and each VM has allocated 8 GB memory, so 48 GB memory of the host, out of its total 96 GB has already consumed.

So I need advise, if one out of 3 host fails, will the % of reserved memory still remain 33% (i.e. available memory from remaining 2 hosts i.e. 96+96=192 & 33% of it i.e. 63 GB will be still reserved)? Or the memory reservation will turn 0% i.e. no reservation since cluster will be left with only 2 hosts?

vCenter & ESXi hosts version: 7.0.x

Thank you.

 

Thank you!
Vikramaditya J
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1 Reply
a_p_
Leadership
Leadership

vSphere will allow you to power on as many VMs as HA can can protect with the configured Admission Control settings.
If one of the hosts fails, this setting will not be applied to the remaining hosts, i.e. your VMs may not get powered on - depending on the remaining resources - in case of another host failure.

André

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