Tape backup is still the most frequently used backup method for business users because of its cost-effectiveness per megabyte of data, despite the increasing popularity of recordable CDs and DVDs. However, just like any technology, tape drives, backup tapes and tape backup software can fail.
There are ways to minimize the chances of a tape backup's failing in the first place. Here are a few tips:
Verify your backups. Most backup software will automatically do a quick "read-after-write" verification and will offer optional full verification. The latter is both more thorough and more time-consuming, roughly doubling the backup time, but if your files are crucial, it makes sense to do a full verification regularly.
Store one backup tape off site. This will ensure your files are preserved if your site experiences a fire, flood or other disaster. Some companies swap backup tapes with other offices. With some smaller businesses, it often makes sense for one employee to take the backup tape home with him. Another option is using an off-site storage firm that provides fire-protected storage facilities for print and digital media as well as tape.
Store your tapes properly. With backup tapes on site, keep them stored in a stable environment, without extreme temperatures, humidity or electromagnetism. Do
- not, for instance, store the tapes in a safe on the opposite side of the wall from a large generator, whose electrical fields can wreck havoc with the data on them.
Rotate tapes. Use more than one backup tape. Instead of using the same tape time after time, rotate through multiple tapes. You can use any of a number of different systems for this. With the odd/even system, you use one tape on one day, a second tape the next day, reuse the first tape on day three, and so on. With the five-day rotation system, you use a different tape for each day of the workweek.
Track the "expiry date." Backup tapes are typically rated to be used from 5,000 to 500,000 times, depending on the type of tape. Tape backup software typically will keep track of the tapes, regardless of the rotation system.
Maintain your equipment. Clean your tape backup drive periodically, following directions in its manual regarding frequency. Consider having an authorized maintenance person from the manufacturer of the tape backup drive or from a third-party repair firm check the alignment of the drive every 12 to 18 months. Most businesses just send the drive back to the manufacturer when it begins to have problems, but if a drive has problems, so can the backup tapes.
Do regular checkups. Periodically test the backup tapes and restore procedures. You can, for instance, restore the data on them to a different server or to a different partition or folder on the same server where the original information is stored.
At the end of the day, never assume your back up technology will never fail. It's just as prone to failure as any other technology. Proper maintenance and testing of your tape technology will mean when threats outside your control jeopardize your data, you can turn to your back ups with confidence and get your business running again smoothly.
About the author: Doug Owens is managing director of CBL Data Recovery Technologies' San Diego laboratory.
This was first published in October 2004