Data Backup

3-2-1 Rule

– Keep 3 copies of any important file: 1 primary
and 2 backups – Keep the files on 2 different media types to
protect against different types of hazards – Store 1 copy offsite (e.g., outside your home
or business facility)

The main idea behind this recommendation is not
to put all your eggs in one basket. Having 2
different devices/disks ensures that a single
hardware failure doesn’t take away all your data.
Similarly, if you store your only backup at home
and the house burns down or gets robbed you lose
everything, that’s what the offsite copy is there
for. Onsite backups give you availability and
speed, offsite give you the resiliency should a
disaster happen.