HA-Change admission control policy on the cluster

Posted on 2014-10-30
Last Modified: 2016-05-17
Dear Experts,
Can we use in VMware HA, the Percentage of cluster resources reserved as failover spare capacity as admission control with two hosts.
Question by:Galame
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LVL 121
ID: 40413334
VMware HA when enabled by default, will require your other server to have the same resource CPU and Memory available for a FAILOVER.

Usually memory is the bottleneck.

So if you have enough space memory available on your others hosts you will not have an issue.

Author Comment

ID: 40413371
So, I want make sure in two hypervisor cluster scenario the percentage admission control is accurate. Is it?
LVL 121
ID: 40413444
What are you resources, how much memory is in use on host1?

how much is free on host2?

Also remember Admission Control is only a safeguard to prevent poor performance, on host2, when a HA action occurs, on host1 failure.

So if host1 is fully loaded, and it's a 64GB host, you will need host2+64GB
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Author Comment

ID: 40413543
Each hypervisor have 12x2.6 GHz and the usage is about 1100 MHz used in each one.
LVL 121
ID: 40413566
CPU will not be the issue, Memory will be the issue!

So do you have enough memory for Host 2?

Author Comment

ID: 40413606
host1 capacity is 140000 MB and the used is 50000 MB
host2 capacity 140000 MB and the used is 40000 MB
LVL 121

Accepted Solution

Andrew Hancock (VMware vExpert / EE MVE^2) earned 500 total points
ID: 40413635
You'll have no issues, currently, you have plenty of spare resources.

You will be able to demonstrate this, by putting a host into maintenance mode.

Author Comment

ID: 40413656

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