The hype around the new vSphere 5.1 is going strong these days, and many people downloaded and installed it as soon as the binaries were available. Many of them installed it upgrading their current 5.0 environment, but they got many problems with Veeam 6.1 jobs failing with errors.

In one sentence: vSphere 5.1 is NOT supported on Veeam 6.1. You need to wait for 6.5. Dot.

If you care about your environment, your due diligence is to check before all the release notes coming out from VMware along with the new release. There are many changes that involve many aspects, and in a production environment you have to be sure every piece of your infrastructure is compatible with each other. Storage firmwares (read here for problems with Synology), View installations (none is supported yet, read here), and if you came here for some uuid errors, yes even Veeam Backup 6.1.

Maish Saidel-Keesing did a wonderful job by commenting the complete release notes, highlighting all the doubt and issues. Go here and read it carefully.

Only when all your components are ready for vSphere 5.1, you can safely upgrade.

If you upgraded vSphere to 5.1 probably now your Veeam backups are failing with this error:

Error: Host with uuid ‘30303734-3536-5a43-4339-343030543957’ was not found

well, first of all remember, you are not supported. Keeping this in mind, there is a little trick at least to make your backups run again: go to Veeam licensing, revoke the licenses applied to ESXi 5.0 hosts, so Veeam can hopefully reassign the same licenses to ESXi 5.1 hosts.

Even with this workaround, I have not tested anything with vSphere 5.1, so I do not know for example if virtual machines with virtual hardware 9 will be supported or not.

Data protection of your virtualized infrastructure is important, are you sure you want to screw everything just to be cool and tell the world you are among the first using vSphere 5.1? There is a compelling reason to upgrade? Some new feature you desperately need?