Worried About Your VM Snapshots? You Should Be
Let me start by saying that I love VMware VM snapshots! The number of use-cases I have for this feature is lengthy, and I have had significant success in putting snapshots into use for upgrades, cloning, testing, and many other scenarios. That being said, it is important that we fully understand why snapshots can be problematic, bordering on dangerous when used incorrectly.
VM Snapshots Are Not Backups
The number one question I get from people is “How can I use VMware snapshots as backups?” to which I answer succinctly with “Don’t”. While VM snapshots are a great tool for rollback capability when doing system updates and changes to your in-guest operating systems, these are not meant to be used as long term backups.
Snapshots, when left for long periods of time, become large and terribly inefficient. You will end up with performance issues as the delta changes are written to the temporary VMDK files. Your storage footprint in these situations will become unruly if a very short time.
Hardware Snapshots FTW!
Using your native LUN/volume snapshots will be much more viable for long term. Using the vendor provided tools from your enterprise storage array should be used in conjunction with VM snapshots to build your overall operational protection portfolio.
To understand more about how VMware storage deals with snapshots, you can read this great post by Marcel van den Berg here: What are the dangers of snapshots and how to avoid?