ESXi acts as a really flexible and powerful monster of an operating system which can easily divvy up your server’s physical hardware in to virtualised components. These components can then be shared among tens of virtual machines depending on how you’ve set things up.
Although flexible and powerful, I could not find any straight forward back-up guides for backing up my virtual machines.
Snapshots are in no way shape or form back-ups so that is out of the question. I did take a look at copying the VMs out of the data store either through the vSphere client or SSH but that is a bit messy.