[English]Today a short note for administrators of Windows Server 2012 R2 who intends to install update KB4036479. This update shall prevents restarts in Hyper-V, but is causing install issues.
Blog reader Marco R. shared his experiences with me via e-mail (thanks for that). Here are the details.
What is KB4036479 for?
Update KB4036479 (Eliminate restarts in virtual machine initial configuration in Windows Server 2012 R2) is intended to eliminate restarts in Hyper-V VMs under Windows Server 2012 R2. Microsoft says in the linked KB article:
When you create a virtual machine by using Hyper-V in Windows Server 2012 R2, a restart occurs during initial machine configuration (IMC). This update eliminates the restart step in the IMC process.
The packet is shipped via Windows Update, so everything seems fine and many administrators are accepting this update – I guess.
KB4036479 is causing endless reboots
Marco R. tried to install this update on a machine with Windows Server 2012 R2 and observed the following.
KB4036479 caused in his environment endless restarts on his virtual Windows 2012 R2 Servers.
The update is displayed as "Successfully installed" in Windows Event Log after each restart, but shortly afterwards the installation process starts again… and so on. Seems to be such a problem again, where the update is not recognized correctly, whether the update was installed successfully or not.
Actually the update should avoid restarts under Hyper-V, or did I misunderstand something? maybe this info saves another admin a few hours of effort in which he does not install the update.
Perhaps this helps other admins running into this issue.
yep, happening to me too – on Azure
Yep, happening to me on all my Hyper-V servers. Worse, when the update fails with the:
We couldn't complete the updates / Undoing changes
it apparently rolls back every other update which was being done with KB4036479 and then shows all patches as 'Succeeded' in Update history when actually all have failed.
It took quite a bit of experimenting (and reboots) before I managed to narrow it down to this one update.
We just declined the patch in WSUS. After that the clients finished the update process 100%