I was recently going through some old posts on here, and found the one with the clickbaity headline When Backups Go Bad. Despite the title, I thought it was worth looking again at some of the common ways backups can go wrong. A bad backup can be as useless as no backup at all. There is an old phrase that applies perfectly to backups. “One is None. Two is One.”
RAID Instead of Backups
Using RAID instead of backups. Most RAID failures are not simple single disk failures so RAID won’t help. #WhenBackupsGoBad
— Dataquest Int Ltd (@dataq_recovery) March 22, 2016
This is a common one. Although RAID can protect against some hardware failures, it does nothing to protect against corrupt partitions, virus attacks, accidental deletion, formatting, multiple disk failures. The list is endless. Add to this the fact that you can have 12, 24, even 48TB stored in one massive array, and you stand to lose an awful lot of data in one go if the whole thing goes south.
Same Disk, Different Day
Making backups to another partition on the same disk. Disk fails, both copies gone! #WhenBackupsGoBad
— Dataquest Int Ltd (@dataq_recovery) March 22, 2016
There are ways to partition a disk so it appears to the computer as multiple disks. The danger is, if you don’t know there are two physical disks inside the computer, you could be making backups to the same disk. When it fails, both partitions will go with it. Best backup to an external drive and then you know for sure.
Break the Encryption
Making an encrypted backup, but forgetting the password.#WhenBackupsGoBad
— Dataquest Int Ltd (@dataq_recovery) March 22, 2016
Encrypting any data is risky without careful consideration. By design, your encrypted data is not accessible without the password, or perhaps a recovery key that was created during the original setup. If you don’t have either of those keys, you can wave goodbye to the data.
Inbetweener
Restoring computer after making a "backup" to external disk. During the restore, you’ve only got 1 copy! #WhenBackupsGoBad
— Dataquest Int Ltd (@dataq_recovery) March 22, 2016
If you’re ever left with a single copy of your files, you’re on thin ice. If something goes wrong, you’ve lost one copy of the data already. We always suggest multiple backups for this reason.
The Space Maker
Making space on laptop by *moving* data to “backup” drive. It’s not a backup if it’s the only copy! #WhenBackupsGoBad
— Dataquest Int Ltd (@dataq_recovery) March 22, 2016
New computers can have painfully small storage, (hey Apple) so a common solution is to start dumping files off to an external disk. This is fine if you just move over replaceable movies & music, but you have to be prepared to never see those files again. Don’t store all your photos & documents on an external drive unless you keep another copy somewhere. External disks are no more reliable than internal ones and can fail at any time. If anything, the risk of dropping or losing an external drive is higher as they are so small and portable.
I’m sure there are more ways backups go bad. I could probably make this into a regular feature. Remember, when it comes to backups One is None, Two is One…