During an upgrade from Windows 2012 to Windows 2012 R2 I ran across a setting called “Availability” for the VM. High availability is available in a host cluster and is documented at: http://technet.microsoft.com/en-us/library/cc967323.aspx
“Highly available virtual machines, also known as HAVMs, can easily be migrated to a different virtual machine host in a failover cluster to provide continuing service when their current host needs maintenance. If their current host fails, the HAVMs automatically migrate to a different host in the cluster through a process known as failover.”
This blog posts tackles two topics:
1) How to change a virtual machine from high availability to normal availability
2) How to change a virtual machine from normal availability to high availability
How to change a virtual machine from high availability to normal availability
This piqued my interest as I have a couple of domain controllers that are pretty darn important to keep running in my lab. When I was working in VMM the virtual machine appears as checked for highly available, but the option to change this is grayed out.
And looking in Hyper-V manager, there is no such setting.
Digging around I found that in Failover Cluster Manager the virtual was defined as a role.
By removing the role, I was able to change the configuration of the virtual in VMM.
The virtual machine still appears in Hyper-V after removing the role as shown below.
In VMM, I refreshed the virtual machine as shown below.
And the availability configuration is now set to normal.
How to change a virtual machine from normal availability to high availability
I have some domain controllers that I would like to make highly available, so how do I make this change since the option is grayed out? The trick is to move the existing virtual and choose the option to make it highly available as shown below.
After migration the virtual appears with a high availability.
Good additional readings on this topic include: