by Jared Byer
Having a back-up drive is good, but I suggest that you don't stop there. Consider the 3-2-1 backup plan: If the data is important, you should have 3 copies of it on at least 2 different types of media, with at least 1 copy off-site.
Reasons for Backups
Understanding the reasons we need backups also makes clear why a plan like 3-2-1 makes sense.
Reason #1: Hard-Drive Failure. The most common reason for backups is the potential for hard-drive failure. Conventional computer wisdom suggests that a hard drive is more likely to fail in the first year, and that the chances of failure start increasing again after three to five years. However, failures can happen at any time, so it’s important to have regular backups throughout the life of your hard drive.
Reason #2: Corrupted, Deleted, or Overwritten Data. Data stored on hard drives can become corrupted. Modern hard drives are constantly correcting errors, and one of the reasons errors are so likely is because of the incredible storage capacity of hard drives. Individual files can become damaged or unreadable on a hard drive that is still very healthy and reliable. This, along with the occasional accidental deletion or overwriting of a file, shows why incremental backups, which allow you to selectively restore individual files, are useful.
Three Copies of the Data
Hard drives fail, and backups can also fail. It is unlikely but possible that both will fail at the same time. For example, a power surge during the backup process can damage both the primary data source and the backup. Having a third backup that is either off-line or off-site can protect you from these more rare occurrences.
Two Media Types
Because most new computers don't come with floppy disk drives, and because tape drives are not as common as they once were, getting data off one of these items can be a challenge. A faulty tape drive or optical drive might make backups that are also faulty. By backing up to different, newer types of media, such as optical or flash storage in addition to hard drive storage, you can reduce the likelihood that your backed-up data becomes irretrievable due to an obsolete or unreadable media type.
One Off-Site Copy
Even if you use the latest technology to back up your files regularly, your backups might be worthless in the event of theft or natural disaster. That is why it is important to have regular off-site backups. Losing a few hours’, or even a day’s work, while still frustrating and costly, is a minor inconvenience compared to losing a week or more of work.
So remember: Back up your files regularly, have more than one copy of everything, don’t rely on just one backup media type, and keep at least one of the copies of your backup data off-site.
Jared Byer has a degree in economics from the University of Tennessee. He worked in taxes and accounting for 10 years before becoming a state tax analyst at Drake Software. When not at work, working on photography, or writing, Jared spends his time keeping up with new technology and consumer electronics.