Backup Rules

Is your computer backed up? Are you 100% confident your backups are complete and up to date?

I didn't think so.

Here are rules for a secure backup. Trust me — it's not difficult to do well.

1. Like exercise, the best backup is one you will actually do. Automation is essential, unless you are very disciplined.

2. You need two! You never know a backup is bad (corrupted, missing, has been failing without your knowing it) until you need it.

3. Best is to have two using completely different mechanisms. For instance, one might be a copy that runs via a nightly script and another could be a backup program, and each goes to separate media.

4. One should be a total backup (so you can recover everything on your disks and be up and running quickly); the other can be just essential files. The total backup should be hard-drive based.

5. You should have something offsite. You may neglect this, thinking it's only in case of fire, which is not so likely. But you should also think of theft. If a thief takes your computer, they will probably take your USB drive and may scoop up any CDs or DVDs they see. Imagine the relief of having the key files elsewhere. Or the grief of not having them.

This can be a much smaller set (e.g. your e-mail, docs folders, omitting system files and applications). The easy way is to use an online backup service that stores your key files on their servers. There are many. Some are designed as backup (like mozy.com or crashplan.com); some are automatic file or folder sync tools (like dropbox.com). These programs all work with Macs and Windows. Some are Linux-friendly, too. I haven't tried it yet, but Crashplan looks great and you can use it to manage the whole family's backups. 

If you don't want to fuss, just go to mozy.com and have at it.

6. You can use a USB or FireWire external drive, or a separate drive mounted in another computer on your local network.

Tools

I use EMC Retrospect as my primary. It backs up all the Macs and Windows on my network to multiple sets and supports DVD. I have two DVD sets, one of which is in the office.

My secondary is SuperDuper (for Mac) which mirrors the whole drive to a separate disk (you can use the similar Deja Vu or Carbon Copy Cloner).

If you're observant, you'll note I am violating my own rule 5. One of these days soon....

Apple's Time Machine is another great choice for those with recent Macs.

If you have suggestions for backup programs or services, please add a comment.

Revised March 2010

Comments

[keith carlsen]

Our operational system is all SUN Unix. Backup system consists of a StorageTek LTO tape robot and Veritas Netbackup software. Initially backups are written to disks in the Netbackup server and subsequently the backups on the disks are written to tape. Advantages are that even if the robot runs out of blank tapes, backups can still run if there is sufficient space left on the disks. Also, restores of recent data occurs quickly since it's likely there's still a backup up on the disk. Only admin necessary is monitor for errors, and pumping blank tapes into the robot (which requires ejecting some full tapes to make room for the blanks). And restoring old data may require retrieving tapes from the tape cabinet for insertion into robot.

[keith carlsen]

Our operational system is all SUN Unix. Backup subsystem consists of a StorageTek LTO tape robot and Veritas Netbackup software. Backups are initially written to disk array on the Netbackup server. Backups are subsequenty written from the disk array to tape in the robot. Advantages are that backups can still run if there are not blank tapes in the robot so long as there is still space on the disks. Restores of recent data occurs quickly since there is likely still a copy of the data on the disk. Only admin required is to monitor for errors, and pump blank tapes into the robot (which may require ejecting full tapes to make room). And restore of old data may require retrieving tapes from the tape drawers for insertion into the robot.