Why doesn't VMWare DRS automatically migrate VMs when a host is put in maintenance mode?

We have 4 ESXi 5.0 hosts in a VMWare cluster on shared storage (NFS) with DRS and HA on.

We want to perform a memory upgrade on one of the hosts. We put that host in maintenance mode but DRS did not automatically live migrate the VMs.

I'm thinking it has something to do with our settings:

I'm admittedly not that familiar with with VMWare's DRS. Can someone offer us some guidance on this?

Solution 1:

This should work, but there's more about your environment that we'd need to know. Your issue is most likely tied to the Admission Control settings for your 4-host cluster. The specifics of how to configure Admission Control properly is outside the scope of this question, though.

Can you try disabling HA Admission control and attempting the Maintenance Mode on the host again?