Feeds

IBM's monster tape will take three days to fill

35TB cartridge poses whole new set of problems

Internet Security Threat Report 2014

IBM Research has devised technology with FujiFilm to create a 35TB capacity tape, but it will take 3 days to write the data at LTO5 speeds.

The new hyper-capacity half inch tape technology has been successfully read and written at a 29.5bn bits/sq in areal density, which means a tape capacity of 35TB according to the researchers. This is said to be 44 times the 800MB raw density of LTO4 tape. From a technological point of view the gee whiz factor is impressive.

The media is FujiFilm's Nanocubic tape, with an ultra-fine, perpendicularly-oriented barium-ferrite magnetic medium that apparently does not use expensive metal sputtering or evaporation coating methods. IBM has developed new servo control technologies enabling a 25X increase in the number of parallel tracks on half inch tape, with a track width of less than 0.45 micrometers.

There is an ultra-narrow 0.2um data reader head and a data read channel based on a data-dependent noise-predictive, maximum-likelihood (DD-NPML) detection scheme developed at IBM Research in Zurich. IBM Research at Almaden developed a reduced-friction head assembly allowing the use of smoother magnetic tapes and an advanced GMR (Giant Magneto-Resistive) head module incorporating optimised servo readers.

The capacity can be increased to the 100bn bit/sq in level according to the IBM researchers. However, one issue that IBM and FujiFilm do not discuss is the time to read or write 35TB of tape data. Using LTO5's tape transfer speed of 140MB/sec it would take 2.89 days (69.44 hours) to write the full 35TB. To write 35TB in the same time that LTO5 writes its 1.5TB of raw data, that's 2.98 hours, would require the tape speed to increase 23.33 times, and that assumes that read/write heads can process the signals passing to and from the tape that quickly.

Accelerating tape speed 23.33X would also increase the risk of tape deformation or breakage and require more electricity for the drive. It seems likely that either multiple-head tape drives or greatly increasing the number of tracks readable by a single head would be needed to be developed to cut the tape read/write times down to more practicable levels. A back of an envelope calculation suggests a 4-head drive or drive which read 4 times as many tracks would cut the 35TB read/write time to 17.36 hours. Another possibility would be to stripe the data across two or more tape drives. A 4-drive setup using such heads would deal with 35TB in 4.34 hours and that starts looking reasonable.

Such striping across multi-headed drives implies a tape library using 35TB cartridges would need more drives and more robotic capability to move cartridges between slots and drives, such that, for example, four cartridges could be delivered to four drives simultaneously. If tape libraries are forecast to sustain their usability because tape storage economics are going to outstrip those of disk for many more years, then changes to allow tape cartridge striping, multi-headed drives, and multiple simultaneous cartridge loading into drives look necessary. ®

Beginner's guide to SSL certificates

More from The Register

next story
Docker's app containers are coming to Windows Server, says Microsoft
MS chases app deployment speeds already enjoyed by Linux devs
'Hmm, why CAN'T I run a water pipe through that rack of media servers?'
Leaving Las Vegas for Armenia kludging and Dubai dune bashing
'Urika': Cray unveils new 1,500-core big data crunching monster
6TB of DRAM, 38TB of SSD flash and 120TB of disk storage
Facebook slurps 'paste sites' for STOLEN passwords, sprinkles on hash and salt
Zuck's ad empire DOESN'T see details in plain text. Phew!
SDI wars: WTF is software defined infrastructure?
This time we play for ALL the marbles
Windows 10: Forget Cloudobile, put Security and Privacy First
But - dammit - It would be insane to say 'don't collect, because NSA'
Oracle hires former SAP exec for cloudy push
'We know Larry said cloud was gibberish, and insane, and idiotic, but...'
Symantec backs out of Backup Exec: Plans to can appliance in Jan
Will still provide support to existing customers
prev story

Whitepapers

Forging a new future with identity relationship management
Learn about ForgeRock's next generation IRM platform and how it is designed to empower CEOS's and enterprises to engage with consumers.
Why cloud backup?
Combining the latest advancements in disk-based backup with secure, integrated, cloud technologies offer organizations fast and assured recovery of their critical enterprise data.
Win a year’s supply of chocolate
There is no techie angle to this competition so we're not going to pretend there is, but everyone loves chocolate so who cares.
High Performance for All
While HPC is not new, it has traditionally been seen as a specialist area – is it now geared up to meet more mainstream requirements?
Intelligent flash storage arrays
Tegile Intelligent Storage Arrays with IntelliFlash helps IT boost storage utilization and effciency while delivering unmatched storage savings and performance.