DRS doesn't take into account affinity rules

[bhouse-nexthop]

problem

It appears DRS doesn't take into account affinity rules when rebalancing. I've got 5 VMs in a non-strict host anti-affinity group (I do non-strict since I have 5 total hosts, and if I take one down for maintenance its ok to co-locate during that duration).

I manually put one VM on each host, then run DRS and I can see it tries to move those VMs in the anti-affinity group so they're co-located on the same host even though there are other eligible VMs that can be moved to rebalance instead.

versions

4.22.0.0 on Ubuntu 24.04 with KVM

The steps to reproduce the bug

Steps in problem description

What to do about it?

DRS should be affinity-aware

[vishesh92]

@bhouse-nexthop DRS is affinity aware. But since you are using non-strict affinity groups, it allows the live migration.

For non-strict affinity groups you will still be able to live migrate the VMs to any host because the affinity group is non-strict. So, this is the intended behavior as of now.