Tape backup is still the most frequently used back-up 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, back-up tapes, and tape backup, software can fail.
These failures can be just a case of bad luck, but sometimes they are the result of just plain lack of planning and foresight. First, having a back-up system next to the main system is not going to do you much good if the threat is a flood that sweeps through your building. Second, just like an automobile that needs an oil change to keep its engine from seizing up, tape systems need proper maintenance.
There are ways to minimize the chances of a tape backup’s failing in the first place. While some of them seem obvious, many organizations simply don’t allocate the staff or the time to make sure these things happen. Regardless of what backup system you put in place, tape or otherwise, make sure someone is responsible for maintaining it and that it is well documented.
When it comes to tape systems specifically, here some guidelines:
Alignment and cleaning – Clean your tape back-up 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 back-up tapes.
Proper storage – With backup tapes onsite, 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.
Tape rotation – Use more than one back-up 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.
Tape lifecycle – Back-up tapes are typically rated to be used from 5,000 to 500,000 times, depending on the type of tape. Tape back-up software typically will keep track of the tapes, regardless of the rotation system.
Fire drills – Periodically test the back-up 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.
Backup verification – Most back-up software will automatically do a quick “read-after-write” verification and will optionally do a full verification. The latter is both more thorough and more time-consuming, roughly doubling the back-up time. But if your files are crucial, it makes sense to do a full verification regularly.
Offsite storage – This will ensure your files are preserved if your site experiences a fire, flood, or other disaster. Some companies swap back-up tapes with other offices. With some smaller businesses, it often makes sense for one employee to take the back-up 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.
It’s never a question of if data loss will happen; it’s a question of when. There’s no point in patting yourself on the back for implementing a tape-based back-up system if you’re not prepared to take care of it. Threats evolve and your data changes, so your disaster recovery preparation must be dynamic.
The cliché that an ounce of prevention is worth a pound of cure has never been truer than in the disaster recovery business. Just ask those who’ve lost their data!
Doug Owens is director of CBL Data Recovery Technologies’ San Diego research and recovery lab, where he specializes in tape technology. Owens has provided tape-related training to the government of Singapore. E-mail him at dowens@cbltech.com.
