Tape Life

[john hamilton]

We are experiencing problems with our tape drive requesting cleaning on almost a daily basis and then not ejecting the tape. I started wondering if some of our backup tapes might be too old. We have some tapes in our 20 tape cycle that have been used 19 to 20 times. How long should a tape last?

[thomasr]

The answer to "How long will a tape last?" is a bit like asking, "How long will my vehicle's tires last?"

The details are below. But let me put recommended actions here up front: Download HP's Library and Tape Tools from hp.com/go/tape and run diagnostics on both the tape and the drive(s). NOTE: The media tests will OVERWRITE all data on a tape, so make sure you do not test a tape with business-critical data on it!. Report back on the results. You can also generate a support ticket on the drive and post it here.

Back to tape media life: It depends not only on how much they're driven, what brand they are, how you drive, and the conditions under which the tires are both used, and stored when not in use.

What type of tape drive are you using? Which brand of media? HP media really is tested to the highest standards; some tape that fails our testing is sold at retail by other manufacturers.

If you're not feeding your tape drives data fast enough to keep them streaming, you'll contribute to early media and drive mechanism failure. For DAT, AIT, DLT, the number you're looking for is NativeTapeSpeed * DataCompressionRatio (plus a safety factor of at least 1.5 - 2.0 to ensure the buffer doesn't empty). Since HP's LTO drives use adaptive write speed, the formula is as above, but divide by 3.

If you can't hit that number, the tape will have to stop, rewind, restart an inordinate number of times, and will wear the tape out much sooner than it's "normal" life.

Also -- where are your tape drives? Are they near a printer? Near the floor? In a dusty environment, or one with sulfur or magnetic particles in the air? Those are known to make for trouble with tape drives and other electronic equipment.

How is your media stored? It should be stored at the correct temperature, standing "on edge", not laid down flat... although this is not likely to be a problem for short-term storage with frequent tape rotation, it may be a problem for archived tape. The humidity should also be controlled, and the temperature both in spec and not varying too quickly. And of course, it's *really* important to not put a tape cold enough to condense moisture in to a tape drive!


For details about life of HP media, see http://h18004.www1.hp.com/storage/tapestorage/storagemedia/tape_ultrium/index.html :
For LTO media, HP says, "Under optimum environmental conditions, Hewlett-Packard LTO cartridges are currently specified to 1,000,000 passes over any part of the tape. In operational terms, this can be translated to about 2000 full backup or restore operations. Under severe environmental conditions, particularly where the tape drive is used at very low humidity or if certain areas of the tape are accessed frequently, the number of backup operations should be limited even further." and, "HP warrants LTO-4 Ultrium 1.6TB RW and WORM cartridges for up to 30 years archival life and/or 260 full backups. This ensures businesses can meet the ever increasing demands of regulation for data retention and archiving."

One last question -- is it possible that your cleaning tape is just All Used Up?