Saving storage capacity on Hyper-V host

Hello,

Storage for Hyper-V host isn’t so cheap, that’s even more true with high availability.

This is something you may don’t know, but by default, when you create a new VM, the “Automatic Stop Action” is “Save” :

Hyper-V-AutomaticStopAction

As you can read on the screen-shot, the hypervisor will reserve the VM amount of RAM on the physical host disk (or SAN/SOFS) in the VM folder :

Hyper-V-MemoryReservationFile

It can be pretty invasive with pretty big host, and pretty useless if the VM is on a cluster. Indeed, in a cluster, if a host shutdown, the VM will live migrate to an other host in the cluster.

Also, if you have a a personal lab on your laptop with a limited SSD capacity, it can save up some precious GB.

To disable that reservation, you can select one of the two other possibility, buy the GUI, or :

Get-VM | Set-VM -AutomaticStopAction ShutDown

This will affect all of the VM on the host.

Note : You need the VM to be off to perform that operation.

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