1. Download vCenter 5.1.0a ISO and mount it inside vCenter. If you splitted the components on several servers, use the ISO on the corrisponding server
  2. first of all, SSO. Open a command line, move into the folder “Single Sign On” of the DVD, and run:
    1 VMware-SSO-Server.exe /S /v" /L*v \"%temp%\vim-sso-msi.log\" /qn"

    You can then open %temp% folder in Windows Explorer and monitor the automatic upgrade from here. You will find the log file and a temporary sub-directory. When that directory will disappear, the installation will be completed. Check the log to be sure the upgrade was completed successfully.

  3. After SSO, proceed with Inventory Service. You can run the installer from the Autorun interface of the DVD. It will find out you already have Inventory Service in place and offer you to upgrade. Obviously choose YES, and wait for the upgrade to finish. There will be no interactive screen to deal with.
  4. Third component, Web Client. I usually like to install it even before vCenter, since it’s the only graphical interface to SSO, so if something is not working you could use it to manage SSO. As before, it will automatically discover the previous version and will upgrade it.
  5. Fourth, vCenter Server. Even here, it will automatically discover the previous version and will upgrade it
  6. Last one, Update Manager, if you have installed it.