Hi everyone
First time post, but I have found the forums extremely useful in search engine results so thought I should get involved as much as I can.
Anyway, I have been posed a question regarding Affinity Rules, and I have not been able to find the answer anywhere, so I was hoping someone might be able to point me in the right direction please.
My client gave me a list of VM's that are "pairs" - by that I mean they both act the same, but one is live and the other is only used if the live VM cannot be reached. There is nothing clever powering that, like clustering or HA within the OS's though.
I was asked to ensure that the pair of VM's could not be powered by the same ESXi host, so following the VMware documentation I set up a VM-VM Affinity DRS Rule. I was asked to test it out, and in fairness, it works a treat. However, the outcome is not desired. Unfortunately, I can't give out too much info due to policies, but I'll try my best to explain the set up and issue.
The Rule stops the two VM's from being hosted on the same ESXi host
VM1 is the live server, VM2 is the backup server
Both of the above are in the relevant Rule
There are 8 hosts in the cluster
HA and DRS are enabled on the cluster
ESXi version 4.1
If I manually start a vMotion of VM2, sending it to the host that is currently hosting VM1, the following seems to occur: VM2 vMotion gets to 78% >> DRS Rules are assessed >> VM1 is vMotion'd to a new host >> VM2 vMotion completes when VM1 is off the host
However, I'm told that the client would prefer that the vMotion of VM2 either fails, or the vMotion process automatically sends it elsewhere, rather than invoking a vMotion of VM1.
I'm not entirely sure what happens in case of a real HA event, as I'm sure I read that HA does not consider DRS Rules? Is the above only happening because it's a manual vMotion? Or, is there a better method I have overlooked?
Thanks
Paul