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Ounce of prevention
While the survey didn't reveal any obvious links of tape failures to media format, brand, or library and drive types, the problem persists. Many of the respondents' comments related to the amount of physical handling that tape requires. Best practices, however, suggest a number of ways to reduce tape failures and possible damage to drives:
- Handle tapes as little as possible. Tape vendors say dropping a tape is the most frequent cause of damage. Even if exterior damage isn't apparent, the fall may have caused the tape to push up against interior flanges.
- Read and follow vendor usage specs. Don't confuse shelf life for useful life; if the vendor's ratings use measurements that are difficult to track (passes vs. mounts, for instance), ask the vendor to put the ratings in terms that make sense in your environment. And note that different media formats have different usage specs.
- Store tapes properly. Extreme temperatures and humidity can damage tapes. Make sure they're not exposed to extreme conditions when in transit.
- Match applications to tape technologies. Certain tape technologies are more appropriate to streaming data, while others perform best in start-and-stop conditions.
- Avoid recertified tapes. Used--or recertified--tapes are
cheaper than new ones, but are often of inferior quality.
Tape is here to stay
Despite tape reliability issues that range from minor annoyances to serious problems, there's little question among respondents that tape will remain part of the backup picture for the foreseeable future.
The growing volume of data that needs to be saved, compounded by new exigencies such as regulatory compliance, will ensure that tape remains the medium of choice for long-term storage. Many respondents noted that they were actively involved in researching or implementing disk-based backup systems but, in most cases, the plans involve using disk for backup staging or for daily backups before archiving to tape.
But tape's key asset--portability--also figures prominently in the problems associated with the medium. And while tape may still maintain a cost advantage over disk, CareFirst's Rogers sees tape's hidden costs. "There are still a lot of misconceptions about the cost of tape vs. the cost of disk," says Rogers. He feels that when people say "tape is cheaper, they're going byte for byte what it costs to get in the box, but not the hands-on management."
This was first published in February 2005