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.

Bit Error Rate Favors Tape Reliability Over Disk  - Horison Information Strategies, April 2011

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 21^st century data explosion.” Pg. 6. April, 2011. Horison Information Strategies

Tape More Reliable Than Disk for Long Term Storage – Curtis Preston, June 2011

Summary.

“Tape drives:

1. Write data more reliably than disk
2. Read it after they've written it to make sure they did (where disks often don't do that)
3. 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?

To learn more about Why Tape Rolls On, see parts 1 through 4 of this series discussing the Security, Green Storage, Speed and Density characteristics of tape.

Gartner last month announced the results of an enterprise infrastructure survey conducted with over 1,000 large enterprises -http://www.gartner.com/it/page.jsp?id=1460213 – and they make interesting reading. According to respondents; data growth is the biggest data centre hardware infrastructure challenge for large enterprises. Now, this in itself is probably not surprising – vendors, end-users and other industry analysts have been talking about this challenge for some time. The inescapable truth is that storage demands are growing, and the answer lies somewhere between provisioning greater capacity and making more efficient use of the resources available. What is particularly striking is that 62% of respondents reported that they will be investing in data archiving or retirement by the end of 2011.

From Spectra Logic’s perspective it is particularly encouraging to see data archiving and retirement projects cited by respondents as the most popular response to the challenge of data growth.  Many of the conversations we had recently with end-users at SNW Europe centred around this theme. Backup is still important to customers – after all, disaster recovery will always be a key capability for IT and the wider business – but archiving is moving up the agenda (and rapidly so). Not only was archiving a hot topic of conversation on the show floor at SNW Europe, but our VP of Marketing & Product Management, Molly Rector  gave a very well received presentation entitled Active Archive: Data Protection for the Modern Data Center. Archiving is clearly making the transition from ‘nice to have’ to ‘business imperative’ – (Gartner will have other far cleverer terms for this I’m sure!)

While this is great news for Spectra Logic in terms of validating our position and viewpoint, it also points to a broader trend; customers are clearly beginning to look more closely at some kind of tiering strategy and/or data categorisation. Previously archiving and backup have often wrongly been lumped together under an all-encompassing tier sitting beneath production storage. I would hazard a guess that for a lot of end-user organisations ‘tiering’ has not got much more sophisticated than using disk for production / transactional data and tape for everything else. A number of technologies and drivers are forcing organisations to reassess this approach.

We can't overlook the rise of SSD (another hot topic at SNW), in this movement - it is becoming a viable option for enteprises, but current prices suggest that IT departments will have to carefully assess what data resides on that medium. This may be kicking off a trickle effect, which starts at the top and works its way down the storage hierarchy, with customers doing much closer mapping of data to storage medium and working out the best fit in terms of cost and performance.

Customers will also be looking at what data can be moved off disk altogether, and this is where archiving – specifically active archiving – comes into play. IT departments that investigate active archives will see that this approach is much less of a trade-off in terms of accessibility and performance when compared to disk than they may think. Customers will probably be shocked at just how much data they have sitting on disk which would be much more appropriately stored within an active archive setup. The data is still online and therefore still of value to the business, but on a much more cost-effective medium.

Everything points to a more sophisticated hierarchical approach to data management. Technologies like deduplication and thin-provisioning will play their part in facing up to the challenges caused by data growth, but ultimately a more radical shape-up of storage architectures is required, with active archives a new and very distinct layer.