I've received a lot of questions lately about hard drive backup and disaster recovery and, alas, the tornado in my adoptive hometown in southern Indiana has brought all that to a head.

As people try to rebuild their lives from this devastating event it gives an exclamation point to the importance of family memories. In my case, my main personal computer contains hundreds of e-mails from my late mother, thousands of photographs of my children and my family and a couple of drafts of a book I am completing.

Of course, the loss of life and recovery from injuries take priority over the recovery of computer data. But after an event like this it soon becomes very important to reclaim family memories.

So, before an event like this or what has happened along the Gulf Coast happens, it is important to make a backup of your computer data. If this is business data, especially, it is important to keep one copy of this backup in another location (at your home, business and perhaps a safe deposit box). If your home is destroyed, your data (even backed up to CD or DVD) is likely not to be recovered, either.

In more normal circumstances, a backup to DVD, CD or to an external USB hard drive will do fine. If you use an external USB drive it is very important not to leave the drive running all the time unless you are using it all the time. Heat and wear are what causes hard drives to fail, and it works out much better if you turn the drive off when you are not actively backing up data. (This doesn't apply if you set up an automatic backup routine because, of course, the drive has to be running to successfully perform the backup.)

The discussion, of course, soon becomes what to back up. You have two choices today; one is to back up only your documents and personal items. That way you have copies of your data when your hard drive crashes. Once you replace the drive, you have to reinstall your applications from scratch. The upside of doing it this way is that your backup files are only as large as your data.

The second way is backing up your whole system. The upside of doing this is that when your hard drive goes you simply have to boot from the recovery CD and your entire computer is restored just they way you left it. The downside is time and space: the backups will be too large for DVD but will fit on an external drive.

I frankly would do both if you have important data on your computer. I wrote a couple weeks ago about Acronis True Image, an excellent whole-disk backup utility that will back up your drive and restore it very easily. Acronis has a new version out, and I tested it a couple of nights ago and found it worked just as easily as the previous version.

(Some backup drives also come with backup software; you can give those a try as well.)