First of all, what is a snapshot? A snapshot is an image taken of a disk at a given time. This lets you roll back to a previous version of your disk in the event of a problem. It is also a way to make restoration points of a disk, similar to a backup, but more complete and easier to restore.
Snapshots themselves have been available since April. On the other hand, snapshot 'profiles' are new. These are snapshots that you can schedule in advance, to be taken periodically at pre-determined intervals. We currently have three profiles that you can use:
- minimal profile: with this profile you can schedule a snapshot every 24 hours, saving the last two.
- weekly profile: a snapshot is saved every 24 hours for a week, for a total of 7 snapshots
- security profile - 2 versions per day (one every 6 hours and another every 12 hours), then 1 version every 24 hours for a week, followed by 1 version every 28 days.
Since a picture is worth a thousand words, and no one reads a thousand word blog post, here is a quick diagram showing the restoration points spaced out over time for each kind of profile:
To work, the snapshots require just a little bit more disk quota. It comes to about 10% of the target disk size per snapshot. For example if you havd a disk of 10GB and if you want to activate the minimal profile, you would need 2 free gigabytes, because it takes two snapshots, which is 20% of your total disk space. Likewise, for the same disk, you would need 7 free gigabytes for the weekly profile or 10 gigabytes for the security profile.
If you have a problem with your server, you can simply choose the restoration point that you want to roll back to, and you will have your server back to where it was when the snapshot was taken. You will still need to be careful though, since when you choose a snapshot, all of them that were taken afterwards will be deleted. Previous snapshots remain.
When can/should you use them? There are many applications for snapshots, though they work surprisingly well for system disks. This use allows you to restore in the event that you screwed something up, or if you have data corruption of some kind, like an infection of malware. The major advantage is that once a profile is in place, you no longer need to worry about it: the snapshots are updated automatically and always available.
To create a snapshot, simply go into your disk management interface (because snapshots are created from disks, and not servers), and click on the disk that you want to take a snapshot of. Then, choose the profile that you want to use, and activate it.
For additional information on this, please see our online documentation.