On the previous post I had a chance to review the major backup and recovery options for VMware. I put the discussion in terms of Avamar, but a lot of that is just for convenience. If you want, you can substitute your favorite backup application in place of Avamar, and you will get more or less the same result (minus the deduplication), albeit perhaps with greater operational pain and expense.
In any event, now that I have covered off the mechanics of the three major options, it is time to take a look at the why and the how of it all. Why would I want to choose one option over the other? How do we differentiate between them? Simply put: what is the best way to back up VMware?
I am going to start by breaking one of the cardinal rules of rhetoric. I am going to state my conclusion before my premises. And my conclusion is this:
Everybody that runs transactional applications in a VM should do guest level backup. You may also do image level backup as an additional method of data protection, but guest level backup is necessary. If you are protecting anything other than a transactional application with a Windows guest OS, then an image level backup (generated by vSphere 4.0 and Avamar 5.0) is sufficient. If you are protecting a Linux guest OS machine that is not running a transactional application, then you will likely find that guest level backups are sufficient.
Now why would I insist that guest level backup is the preferred methodology if you are running a transactional application within your guest OS?