Why Tape Technology Just Doesn't Cut It

There have been a raft of tape announcements in the last week, most notably the two 1TB wannabee's IBM and Sun. For around a mere $37,000, plus the cost of a cartridge, I can backup 1TB of my most precious data. HP have also announced plans to extend the life of the DAT/DDS tape drive.



If you are a large enterprise customer then the cost of these drives may be justified (although I struggle to see how, when LTO4 drives can be had for about $5000 a piece) and I'm sure actual versus list price will be much lower.



The thing is, hard drives just continue to outpace tape growth. With 1.5TB drives on the way, and 1TB SATA drives available for less than $200, then disk-to-disk is much more appealing than tape at this rate. Obviously I'm riding roughshod over the issues of disk power consumption and portability but my point is that tape just isn't keeping up the pace in either capacity or throughput.

The whole issue is especially true in the small business area where it is easy to purchase terabytes of primary storage but backup to tape is really time consuming.

Why can't tape produce the equivalent bit density of disk? Is it the more fragile nature of the medium? Clearly tape is more flimsy than a rotating sheet of metal; the T10000 cartridge tape is 6.5 microns thick and the tape itself covers approximately 11.5 square metres, much more than the total surface area of the spinning plates in a hard drive.


I guess we will just have to accept tape capacity will never be good enough. That's just the way it is.


By the way, Sun get a big fat zero in the RSS ratings for not providing their news in RSS feed format....

The Power Question

I've seen a lot of discussion (and I think a bit of a theme at SNW) on power consumption in datacentres. Obviously the subjects of global warming and increased energy prices have put the subject at the centre of focus. But I think when datacentres are being built, there isn't an issue. The problem comes along as the datacentre fills up with equipment. Invariably, new equipment (especially in the storage world) is coming in denser and requiring more power per rack or square metre. So, as equipment is swapped out and replaced, the original calculations done on how much power per square metre is needed are no longer accurate and the balance tips from one of "have we got the space" for new equipment to one of "can we power the new kit up".

I don't see how this problem will be solved as datacentre planners will always cater for the power/cooling of today's products, not the mythical power demands of future products. Datacentres will therefore have a finite life, after which you may as well start again.

Here's a practical example; There is a manufacturer of highly dense storage arrays (that don't need to be powered up all the time) who can't deploy into a number of London datacentres I know because product density would cause the array to fall to the floor. The datacentres were never designed to take products of that weight...