Information Technology Reference
cost of three hard drives may be hard to swallow.
In my opinion, except for mission-critical business use, two sets each
of duplicates and versioned backups should be adequate for most
users. If you back up to hard drives, this can mean a total of two drives,
each of which is partitioned to store both a duplicate and a versioned
set, your data will be somewhat safer—and your backup routine may
be somewhat easier. But it's better to have fewer sets that you maintain
diligently than to lay out an elaborate plan for multiple sets that you
don't follow because it's too complicated or time-consuming.
In any case, if you have more than one set of media, you certainly
should keep one in another location all the time. That brings us to the
next crucial part of a good backup strategy: offsite backups.
Why Store Backups Offsite?
If someone breaks into your home or office and steals your Mac,
chances are they'll also grab whatever's attached to it, such as your
backup drive! Fires, floods, earthquakes, and other disasters could
likewise wipe out your backups as well as your computer. As much as
we want to believe these things will never happen to us, the prudent
course is to plan as though they will. So I urge you to keep at least one
extra copy of your data far away from your computer. You have quite
a few choices, including physically moving hard drives from place to
place and using an online backup service; I outline the options in Store