Reliability: (adv.) the extent to which an experiment, test, or measuring procedure yields the same results on repeated trials. Dependable. Sure. Trustworthy. (From our friends at Merriam-Webster). And there’s a picture of tape next to the definition. Ok, so maybe the picture statement was a stretch, but associating the definition of reliability with tape definitely is not.
Anybody who’s been in the storage industry for more than 30 minutes has likely heard the phrase, “tape’s not reliable”. Certain marketing machines in the technology space propagate that phrase as much as possible – occasionally with bumper stickers. Those folks have some imagination, but generally register a bit low on the fact meter.
Here are a few things people are saying about the reliability of tape.
Summary.“Tape drives and tape media now have a higher BER and longer useful life than disk products making them better suited for the long-term data retention requirements demanded by fixed content, compliance and archive applications. For a specific amount of data transmitted, tape now has a marked reliability advantage over disk – a surprise for many.”1
1.“Tape: New Game. New rules. Tape re-architects for 21st century data explosion.” Pg. 6. April, 2011. Horison Information Strategies
- Write data more reliably than disk
- Read it after they've written it to make sure they did (where disks often don't do that)
- Have significantly less "bit rot" or "bit flip" than disk drives over time.”2
2.“Tape more reliable than disk for long term storage.” Backup Central blog, June 2, 2011
Tape Drives 700% More Reliable Than 10 Years Ago – Debbie Beach, Sylvatica Consultants, 2009
LTO drives are specified with an impressive mean-time-between-failure rate (MTBF) of 250,000 hours at 100% duty cycle, that’s 700% more than the MTBF of tape technologies created a decade ago.3
3.“The evolving role of tape and disk in the data center.” Pg. 7. 2009, Beech, Debbie; Sylvatica White Paper
One is an accident. Two is a coincidence. Three becomes a trend. The reliability of recording data to tape for storage over the long term is hard to beat. Could that by why tape roles on?