We highly recommend Snapshots as a great way to store a version of your machine should you ever need a backup. You can take Snapshots manually, and also enable the Auto-Snapshot feature.
What is a Snapshot?
A virtual machine (VM) snapshot is a record of a running virtual machine at a point in time. When you take a snapshot of a VM, its storage information (the data on the hard drive) is saved. Where necessary, I/O is temporarily halted while the snapshot is being taken to ensure that a self-consistent disk image can be captured. You can then revert back to that Snapshot whenever you like.
Unlike Templates, snapshots can be created without first shutting down the VM.
How Does Auto-Snapshot Work?
Auto-Snapshot will take a Snapshot for you automatically and store a pre-determined number of Snapshots.
For example, you can set your VM to take a Snapshot once a week, and keep up to 2 of the most recent Snapshots.
Auto-Snapshot can be enabled at machine creation, and also can be added, edited, and removed on the Machine's page in your Console.
How do I Revert to a Snapshot?
Reverting to a snapshot restores the VM to the state it was in at the point in time when the snapshot was created. All changes made to the VM since the snapshot was taken will be discarded and the current state of the VM will be lost.
To revert to a Snapshot, go to your Machine's page in your Console, scroll down to the Snapshot section, and choose the Snapshot you'd like to roll back to. This is not reversible.
Snapshot pricing is based on the size of your instance. Prices below are per month, and Snapshots are prorated for the time that you have them.