Jargon Technology

One of the biggest hurdles you may have to overcome in the upgrade of vCenter to the latest 4.1 platform is the fact that 32bit is no longer an OS option.  With Microsoft abandoning 32bit OS support with the latest Server 2008 R2 offering it should be no surprise that vendors supplying software for Microsoft platforms will have to start releasing only 64bit software.  In my lab my vCenter server is running a semi-unsupported configuration of Server 2008 R2 (now supported with vCenter 4.1) and SQL Server 2008 R2 Express (not supported). 

As always it is best to review VMware’s official KB Article #1022104 for best practices of both ESX/ESXi and vCenter.  Hopefully your vCenter Server is already a 64bit OS so you can skip the whole database migration and server reinstall steps.  That’s the path I will be following here.

1. Once you pop in the CD (or use the ISO or extract and run the autorun.exe) you will notice that there is an Agent Pre-upgrade Check utility. I’d recommend running it just to make sure there are no issues that may prevent or provide problems during the upgrade.
2. The utility requires the database DSN and the login credentials required and then it will provide a Pass/Fail mark and allow you to view a results HTML file, hopefully yours will come up clean like mine.
3. Now you can launch the vCenter Server installer.  You should see a notice about an existing version of vCenter that will be upgraded by this process.  Press Next to proceed.
4. Accept the End-User Patent Agreement by clicking Next.
5. Agree to the End User License Agreement and click Next.
6. Provide Database DNS Options and log-in information if necessary and click Next.
7. State that you want to upgrade your vCenter database.  This will require you to Check the box stating you have backed up your database in case anything goes wrong.  If you haven’t taken a backup now would be the time to open up your database management application and run a quick backup.  Once you have done that click Next.
8. Select how you want the vCenter Agent upgraded, the default (and what I used) was Automatic.  Click Next.
9. Provide the password of the administrative service account running the vCenter Service and click Next.
10. Unless you have changed any of the default ports, leave them unchanged and click Next.
11. The installer will now ask you to estimate the size of your ESX/ESXi environment so it can properly allocate memory to support your environment.  The options are small (less than 100 hosts), medium (100-400 hosts) and large (more than 400 hosts).  Most companies and organizations will fall into the small category unless you have a pretty substantial VMware environment.  Make your selection and click Next.
12. Finally click Install.

Once the installation completes you can update the vSphere client by opening up a web browser and going to http://ipaddressofvcenterserver and downloading and installing the latest vSphere Client.  Once that is updated you can connect to the vCenter server and complete the process of updating the vCenter Agents on the hosts be clicking on each host and reconnecting them to vCenter.  You will notice a task gets kicked off to install the vCenter agent on the hosts.  If you have followed this guide and the one for the ESXi servers you will have an additional component to upgrade, the VMware Tools for each VM.  Once that completes you are good to go.