HA and affinity rules & Duncan & Frank's book

[daunce]

Reading VMware vSphere 5 clustering deepdive by Duncan & Frank (paperback v1.0), I'm confused.

On page 212, second paragraph, it says (roughly) VMware HA is unaware of VM-VM anti affinity rules, and after a HA event may start them on the same host. But on page 215, second paragraph, it says (roughly) HA will not violate mandatory rules after a HA failover.

That appears to contradict itself.

I can't type out the complete section due to copyright.

Anyone able to explain it?

Cheers.

[depping · Accepted solution]

Hi,

There are two types of rules:

1. VM - VM affinity rules
2. VM - Host affinity rules

HA is not aware of the first, VM-VM, so any rule you create here will be ignored by HA.

Now for the second it is slightly more tricky... There are two types of VM - Host affinity rules:

1. Must aka mandatory
2. Should aka preferential

HA will respect "must" rules, but will not respect "should" rules.

This is what the book refers to.

[daunce]

ahhh.. Understood.

Thanks Duncan.

Can the next book have an audio version read by Eric Sloof? That would rock for the drive to work.

[depping]

I could definitely discuss this with Eric... LOL, I had plans originally to record these "nuggets" with Eric that go in to a specific feature. I will discuss it with him again and see what we can do. (We just need to find the time)