We have successfully created two virtual machines using VMware ESXi 4. We are in the process of developing a backup scheme for ESXi, but are unsure of the best method to do so.
After researching on the internet for some time, we have found that there are a number of various ways to backup the virtual machines. Some say to just backup the virtual machines as files (just as you would backup a song or a word document). Others suggest to use cloning within ESXi. Someone else mentioned to just use snapshots and back the snapshots up.
What is the best practice for creating backups of virtual machines that are stored somewhere else (be it a NAS, External HDD, DVD, etc.) which can be easily restored later if needed? What backup method produces the smallest backup size for better storage utilization?
We want to backup the virtual machines, NOT the server itself (the HDD with the hypervisor and everything under it).
Thanks in advance.