HA

[fitzie22]

This could be some of the easiest points you can receive. I have a question that was asked to me and I am 99.9% sure I am correct in it...

Q- Can you single out individual VM's in an HA cluster only. So rather than turn HA on for the whole cluster and all the vm's in that cluster can we just have HA on say 5 vm's

A - No becasue HA is a cluster wide setting in that all vm's under that cluser would utilize HA

Let me know if I am missing anything on this..

[AntonVZhbankov · Accepted solution]

You can customize HA settings for each VM, by default all VMs use cluster settings. And you can select "disable" for both cluster and particular VM. I suppose this means "do not restart".

So, if I'm right, then your answer is wrong.

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VMware vExpert '2009

http://blog.vadmin.ru

[runclear]

Anton is correct....

here is a screenshot of what he is referring to....

[fitzie22]

ok I can see that. But I guess my point would be failove constraints. So if I set all except 5 to not restart in a host failure then does that increase the failover capacity. just an FYI as to why I am asking is becasue we have a cluster that has HA enabled but most (except 5 ) vm's need to have HA enabled. So I am wondering if I set only 5 to restart on another host would that increase the ammount of VM's taht Ic an now have in that cluster?

[Troy_Clavell]

and to go add a little bit to what Anton said, If using 3.5.0U2 or above and vCenter 2.5.0U4, you enabled VMM. VMM will monitor heartbeats of your VM's and restart them on other hosts in the cluster.

2.5U4 fixed some issues with VMM, so if you are not at U4 for vCenter, I wouldn't enable VMM just yet.

[AntonVZhbankov]

If you set "Allow VMs to be powered on even if they violate availability constraints" then you can use all the cluster power, up to 100% load.

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VMware vExpert '2009

http://blog.vadmin.ru

[AntonVZhbankov]

Troy, could you please clarify? As far as I understand, VMM is intended for use on live cluster, not in case of dead host. And it doesn't restart VM on other host in this case, it just restarts VM.

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VMware vExpert '2009

http://blog.vadmin.ru

[fitzie22]

So considering the N + 1 architecture is not needed in my scinerio then keeping the 5 vm's on cluster setting and changing the rest to not restart and set "Allow VMs to be powered on even if they violate availability constraints" I will tehn be able to add more vm's to teh cluster. IN THEORY

[Troy_Clavell]

As far as I understand, VMM is intended for use on live cluster, not in case of dead host. And it doesn't restart VM on other host in this case, it just restarts VM.

Yes, you are correct. I was just adding some information to what you said. If you have HA enabled on a cluster the feature of VMM is available and can be used. All VMM cares about is heartbeats of the VM. I just wanted to let the OP know about this feature if he wasn't aware of it.

[AntonVZhbankov]

N+1 is always least recommended state of HA cluster. In theory. But you have your live machines and you know better what is more important.

Maybe you should think about some standalone ESX hosts, not included to HA cluster? To keep expensive HA license only for those VMs that need it?

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VMware vExpert '2009

http://blog.vadmin.ru

[fitzie22]

Excellent. thanks fot the info