A useful minimum: multiple copies
A business should not rely on a single computer, single external drive or single NAS as its only copy of critical data.
Consider a 3-2-1 approach
- Keep at least three copies of important data
- Use at least two different storage types
- Keep one copy off-site or in an appropriate cloud service
What to define
- Which data is critical
- How much data loss is acceptable
- How quickly systems must be restored
- Who checks that backups actually work
Backups must be tested.
A backup that has never been restored should not be assumed to be reliable.
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