C’est la vie, tape?
Posted in Storage Applications, Platforms, Advisor - Tom Treadway by Tom TreadwayFor a long time now I’ve been a proponent of replacing tape drives with hard drives. But there have always been technical hurdles to overcome involving reliability, “head stickage”, etc. And the tape drive vendors keep increasing their capacity and throughput to just stay ahead of the disk drive folks.
So my Spidy senses started tingling when I saw an article on Byte and Switch announcing ProStor Systems’ new RDX backup technology using hard disks. Hmm, has the time finally come?
RDX is based on standard 2.5” drives found in laptops with capacities up to 400GB. By comparison, the LTO Gen-3 tapes also have a capacity of 400GB. The tape drive folks actual claim a capacity of 800GB using compression, but of course that same compression could be used on hard disks so I’m going to just ignore compression.
The LTO Gen-3 tapes get up to 80MB/s throughput (again, without compression). But the ProStor website shows only 30MB/s. I was a little surprised since modern SATA drives can get closer to 100MB/s. Maybe this is just a limitation of laptop drives. Or ProStor’s “Adaptive Archival™” technology.
Then there’s the question of access time. An LTO Gen-3 tape takes about 80 seconds for a full rewind, and has an average access time of around 45 seconds. Of course a hard drive takes just millisconds for either operation.
Next I checked out pricing. An LTO-3 tape drive costs around $5K. And tape cartridges cost around $100 each. I couldn’t find pricing on the ProStor website, but I would expect a 400GB hard drive to cost around $200. Of course ProStor would have a mark-up on that price.
Bottom line is that LTO tape seems to be keeping a lead on disk backup. And with LTO Gen-4 starting to ship, the tape capacity is jumping up to 800GB with 160MB/s throughput. I just don’t see tape going away in the near future. Pity.
TT