Snapshots vs Backups
What is a snapshot?
A snapshot is an image of your system/volume at a specific point in time. Snapshots and snapshotting technology is available on many enterprise technology systems e.g. Vmware.
What is a backup?
A backup is a duplicate copy of the data. A good backup system should provide:
- A way to recover specific files/data inside the backup.
- Ability to keep copies of backups offsite.
- Keep copies of backups offline.
- On a segregated network.
- Moving the data outside of the primary storage realm into a separate storage domain.
- Backups should be cheaper than snapshots (i.e. backups on lower storage class).
What is the difference between a backup and a snapshot?
Snapshots help us quickly recover the system and put it back into a working state. For example we take a snapshot before we upgrade a system. We upgrade the system and something goes wrong. We can really quickly and easily restore the snapshot we took earlier.
In the scenario above, we could have also taken a backup and recovered from that; but usually this would take longer and bit more clunky. Backups are better suited to helping us recover from a major/catastrophic disaster, event or failure. Some examples:
- A cyber-attack where the network has been compromised. A storage system containing sensitive data has been compromised with ransomware it’s the same system that provided snapshots to protect the data.
- Your data centre or data centres have been hit by a major natural disaster or terrorist attack. The primary system that contained the data and the systems providing snapshots are destroyed.
For the most part, snapshot technology is so good these days that it seems like there’s no need for backups anymore. But remember if all else fails you should have backups, which in the worst case scenario, can help you recover from an offsite/offline copy of your data. You might lose some data.