There's no magic to preventing major problems with tape backup systems. Often all that's needed is ordinary care and a little knowledge -- tape backup problems are almost always avoidable. If the tape system is properly installed, configured, maintained and operated, it is highly reliable. However, it does require some effort and knowledge on the part of the storage/backup administrator to make this happen.
"A lot of the pain associated with tape stems from drives, media and the ecosystem," said Eric Bassier, product manager for tape automation at Quantum Corp., a major manufacturer of tapes and hardware. "If you size your tape system properly, based on capacity and throughput, and if you follow best practices in terms of backing up incrementally with maybe a weekly full backup, keep tapes stored separately, handle your media properly and keep it in a clean, dry place at room temperature, that should take care of almost all the issues people see with tape.
You should always make sure your tape system is properly configured. A configuration or driver mismatch can cause all sorts of odd and intermittent errors. Configuration and drivers are one of the places to look if you're having repeated failures or error messages that aren't fixed by usual remedies such as cleaning the drive or replacing the tape. Also suspect configuration or driver problems if the backup system is running unusually slow.
In configuring your tape drive, the vendor's documentation is your friend. Study the docs carefully and make sure that you apply the recommended settings exactly. If you're having problems, go back and check the manuals carefully to make sure everything is set as it should be.
Get the most recent drivers off the vendor's website and make sure the drivers on the server and the tape drive match. It's also important that your tape system and connection be properly sized. A drive without enough throughput or capacity or a connection to the system without enough bandwidth will both produce problems.
Check your tape system's error log frequently
Check the tape system's error log regularly. Often it will provide an early warning of potential trouble. This is especially true in modern tape systems where the manufacturers have gone to considerable lengths to make the system's operation more transparent. A series of errors that don't cause failure can alert you to take action before the system fails.
Dirty drives and tape media can cause failures. "We recommend to our small business customers that they regularly clean their tape drives using cleaning media [a tape cleaning cartridge]," said Bassier. "If you don't clean tape drives from time to time stuff can build up in the drive and that can cause problems." Although the interval between cleanings will vary with the amount of use the drive is getting and the environment it is in, a common schedule is to clean the drives once a week. Your drive's documentation should contain information on recommended cleaning schedules.
Also keep in mind that cleaning cartridges have a finite life span. Many of them are rated for 50 or so cleanings before they should be discarded. Know and follow the recommended number of cleanings before replacing the cleaning cartridge.
By the same token the tapes themselves need to be protected from dirt and dust. Always keep tapes either in the drive library (or drive) or in their cases.
It's also important to store tapes properly. The most common problems, Bassier said, are temperature and environmental contaminants. LTO tapes in particular have stringent temperature requirements and the lifespan deteriorates drastically if the tapes are stored too hot or too cold. In general, Bassier said, room temperature is fine for tapes.
Test your backups regularly to make sure you are actually backing up your data. If possible, use your software's "compare after backup" feature to make sure the data is being written correctly to the tape at every backup. (This effectively doubles the time it takes to do a backup so you may not have a long enough backup window.) Use your backup software's test restore feature at least monthly or try recovering files and documents at random.
A large percentage of tape problems are operator related. Proper training means more than "insert the tape and push this button before you leave for the day." Make sure your operators are properly trained, including basic troubleshooting and familiarity with the most important error messages and what they mean.
Have a well-established data backup and recovery procedure. For example, a common tape rotation schedule is to make an incremental backup each night and a full backup once a week, taking the full backup tapes off site on a son-father-grandfather rotation.
To keep your data safe in the event of a disaster, make sure to store a full backup remotely. "It makes sense to store those tapes off site for disaster recovery so if something happens to the facility you're protected," said Bassier. You want to have your data somewhere else for disaster recovery purposes.
About the author: Rick Cook has been writing about mass storage since the days when the term meant an 80 K floppy disk. The computers he learned on used ferrite cores and magnetic drums. For the last 20 years, he has been a freelance writer specializing in storage and other computer issues.
