What makes a good backup?
While most people understand that they should be backing up their data, we want to avoid as much effort and cost as possible while doing so. So we end up doing all kinds of things: storing extra copies on our computer in a different folder, keeping some key files on an external USB pen drive, burning CD’s, etc. But are these methods sufficient?
In order for a backup to truly live up to its name, it must fulfill three criteria. A backup of any digital data must…
- Have no ties to the original copy
- Reside on a separate physical platform
- Be stored in a separate physical location
No ties to the original copy
If part of your backup is dependent on something that is not backed up and cannot be readily replicated, your backup is as good as useless. For example, when you back up Word documents, you don’t have to back up the entire Word program as well, since you can reinstall the software from the CD’s it came on. You can make the same argument with PDF’s and Adobe Acrobat Reader.
However it’s a different story if we consider encrypted files. High-level encryption sometimes involves the use of a key file, a special file which is required to open an encrypted file. The data is stored in the encrypted file is completely useless if you don’t also have a copy of the key, so a backup of the key should also be made.
Separate physical platform
Once the backup copy is completely unique, we have to get it onto a different system from the original. So if my original Word document sits in the “My Documents” folder of my machine, storing the “backup” in C:\backup on the same machine doesn’t cut it. If that machine dies —specifically, if the hard drive inside that machine fails — both copies are gone.
Many newer desktop computers today come with more than one hard drive, so you may think that storing the backup on the second drive is sufficient. However, this won’t protect you in the event that the whole computer is stolen or destroyed (usually through fire, flood, or damage while moving).
The only way to satisfy this requirement is to get the backup onto an external storage device of some kind. CD’s, external hard drives, and USB pen drives all meet this requirement. However they too are completely worthless if you don’t fulfill the last requirement…
Separate physical location
Let’s say you stored a full backup copy on a USB pen drive. If that USB key simply stays plugged into the computer or sits on/in your desk, you are still vulnerable to the same fire/flood/burglary risks described earlier. Thieves can ransack a whole house, while fires and floods destroy everything in their path. So to completely eliminate this risk, the backup must stay in another building.
Taking what we’ve learned here, a semi-secure, economical home backup solution today would be a large-capacity USB pen drive that holds extra copies of your critical data and lives at your office, friend’s house, etc. You’d still be at risk any time the drive was at the original location, e.g. you brought the drive home from work to backup some data, and will take it back into the office in the morning. It’s also extremely work intensive.
Desktop backup software, like Mozy and Carbonite, plus our own Fwd:Vault, can offer more thorough backups that are instantly more reliable: your data fits the 3 backup criteria as soon as the backup process completes. In exchange you pay a monthly or annual fee, and must install and configure the backup software (Fwd:Vault does not have any software requirements).
Ultimately, the backup setup you choose should depend on your needs and situation, but at least now you know what must happen in order to truly secure your data.
