VMware vSphere Auto Start and HA clusters

I’ve just been reading through various VMware documentation as part of my VCAP-DCD5 study and I was going over HA specific configuration. It was here that I found a particular note that in all honesty did not realise until now…Auto Start of VM’s is not supported with an HA cluster!

I guess I can see why this is the case but it never occurred to me as the option was always available to me even when HA was configured.

It then prompted me to look for more information and came across a blog post written by Michael Webster: http://longwhiteclouds.com/2012/03/28/auto-start-breaks-in-5-0-update-1-not-just-free-vsphere-hypervisor-version/

It turns out that in the latest vSphere 5 update this is finally disabled in the GUI and cannot be configured when HA is enabled.

This is good to know as we have always had both configured particularly for power outage scenarios where we don’t want to rely on the manual startup of VM’s. We have over 30 sites and at particular times of the year full site outages are common. Also, as Michael has mentioned this could cause problems when using a Virtual SAN Appliance such as the HP P4000 VSA. These use local VM’s that present the hosts local disk as iSCSI storage to a cluster. If these did not automatically start when a host was powered on there would be no shared storage and as such no VM’s to power on.

I suppose with good process and procedure these sorts of situations can be dealt with but it is something to keep in mind particularly for remote sites where support is limited.