Half the VM reboots on Patch Tuesday

Virtual machine snapshots are a quick way to recover from unexpected incompatibilities you may encounter when patching guest operating systems.  In fact, VMware Update Manager even provides an option to automatically snapshot a VM before applying updates and then delete the snapshot after a specified amount of time.

Even if you are not using VMware Update Manager, a typical patch workflow may look something like this:

  1. Take VM snapshot
  2. Apply updates, which normally require that you…
  3. Reboot
  4. Test
  5. Remove snapshot

After I wrote yesterday’s post on Hyper-V snapshots, something occurred to me.  The 5 steps above are only for VMware ESX.  If you are using Hyper-V as your platform, you are not done yet — the snapshot differences are not actually merged until the VM is powered off.

Hyper-V administrators, please add the following steps:

  1. Power off VM
  2. Wait for merge to finish
  3. Power on VM

Patch Tuesday. Would you like one reboot or two?

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1 comment

  1. Vladan’s avatar

    This is really not cool. Wits Hyper-v you’ll have 2nd reboot for your VM under Windows.

    This makes the unavailability of your host even longer. Thanks Microsoft. Oh my god.

    I still did not figured out how to prevent the automatic reboot after update on 2008 server. It’s pretty anoying.

    Cheers,
    Vladan

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