Create an offline snapshot of a VM

We’re currently thinking about automating Windows Updates and the involved disaster snapshot-copy to a degree, where we don’t need to intervene anymore.

Right now, we already have a rudimentary scheduler in place, which does the reboots for some (200 ..) systems already. Now, we’d like to extend it to also cover the bi-weekly Windows Update spree.

Since PowerShell (and PowerCLI) work quite well with vSphere automation, I cooked up the below script to first shutdown a virtual machine (for snapshot consistency reasons), then take a snapshot and power on the virtual machine again afterwards.

Modified SnapReminder

Well, PowerCLI makes my life a little bit easier. Believe it or not, each of us vCenter infrastructure admins has one of these: a Windows admin, thinking a snapshot is also a backup. Thankfully, Alan Renouf over at wrote the SnapReminder, which already helped me a lot! However, occasionally the script isn’t finding the snapshot author (for whatever reason).

Since I want a notification in that case, I modified the script a little bit to suit my needs.