An update rollup is a bundle of bug fixes, and Microsoft appears to be releasing them on a regular basis for System Center. You can download update rollups from the Microsoft Update Catalog, or you can configure WSUS or the Configuration Manager to download/deploy the updates on your behalf.
Usually the process of deploying an update rollup to System Center is very simple: The package is downloaded and installed. However, it appears that there was an issue with the previously released Update Rollup 1 (UR1) for System Center 2012 SP1 – Virtual Machine Manager (VMM).
According to Carmen Summers (System Center, CDM Sustained Engineering Lead): “When Update Rollup 2 is applied to a system which is running System Center 2012 SP1 Virtual Machine Manager with UR1, the installer does not patch files correctly. This is caused by the way UR 1 was packaged.”
As a result of this packaging issue with UR1 for VMM 2012 SP1 (KB2792926), Microsoft is giving us the following advice so we can correctly install the recently released UR2 for VMM:
– If you download Update Rollup 2 package for System Center 2012 SP1 Virtual Machine Manager from Microsoft Update Catalog and install Update Rollup 2 without un-installing Update Rollup 1, you should un-install Update Rollup 2 package for Virtual Machine Manager and then un-install Update Rollup 1 for System Center 2012 SP1 – Virtual Machine Manager via control panel.
– If you are using WSUS to update System Center 2012 SP1 – Virtual Machine Manager and you have already installed Update Rollup 1 for System Center 2012 SP1 – Virtual Machine Manager, then you will not receive Update Rollup 2 notification until Update Rollup 1 is uninstalled.
This might sound complicated at first, but the process should be simple and quick to complete. Remember that all of the value of VMM is contained within the VMM database and the library shares. Even if something was to go wrong (which it should not), you can get all of that data back with an uninstall and reinstall – this assumes that you have used the option to use Distributed Key Management to store the encryption key for sensitive data such as Run As accounts.