Feeds

Helium: Can it prevent the onset of Shingles?

Blimp gas is the write stuff

HP ProLiant Gen8: Integrated lifecycle automation

Blocks and Files Filling disk drives with helium gas delays the time when shingled magnetic recording has to be adopted.

That's because helium gas-filled drives can cram more platters into a disk drive enclosure, thus increasing capacity without having to alter the data recording method. The current PMR (Perpendicular Magnetic Recording) process is nearing the end of its development as any further decrease in the size of the magnetised bits renders them unstable, and if you can't store data reliably then that's game over.

It is coming generally clear that PMR has to be followed by an energy-assisted recording method, such as Seagate's Heat-Assisted Magnetic Recording (HAMR), where localised heating of a bit is needed to alter its magnetic state, thus making it more stable and resistant to change at room temperature. But the development and implementation of HAMR-like technology could cost billions of dollars.

Enter Shingled Magnetic Recording (SMR) - we won't be vulgar and call it Herpes Zoster Recording although like that form of shingles it is undesirable - as an intermediate step. It uses PMR recording but partially overlaps tracks when writing, leaving narrower read tracks, and so crams more tracks onto a disk's surface thus increasing capacity. There is a major re-write problem though, as rewriting bits on one track alters the bits on the overlaid tracks. They have to be recovered first and then re-written, which slows rewriting down. SMR drives can't be used when fast writes are needed.

With helium-filled drives, Hitachi GST says, you use PMR recording but the resistance to spinning the disks in a helium environment is one tenth that of everyday air. This opens the way to having more platters in a standard drive enclosure, seven instead of four in a present day 4TB, 3.5-inch form factor drive, giving you 75 per cent more capacity and no diminution in write speed. Possibly the platters can be thinner, too.

Only WD subsidiary HGST has helium-filled drive technology, having cracked - it says - the notorious problem of helium leakage after many years of development. This implies it will take competitors Seagate and Toshiba some years to catch up while WD should inherit HGST's technology at no cost.

HGST can create a 7TB drive without using SMR or upgrading PMR technology, whereas Seagate and Toshiba will have to go to SMR, upgrade PMR technology into uncharted waters or go for a post-PMR recording technology. All three options involve spending money or entering the SMR world of slow writes.

Roof shingles

Roof shingles

Meanwhile HGST pumps gas into its drives, uses existing PMR and increases capacity by up to 75 per cent. I'd call that sitting pretty, and it can go to SMR if it needs to and increase capacity again, thus maintaining a capacity advantage over Seagate and Toshiba.

Shingled writing

Shingled magnetic recording

This assumes HGST (Helium Gas Storage Technology?) helium tech is solid and its drives won't leak and lose their helium-filled goodness. THere's also the point that increasing the platter and head count by up to three quarters could increase the number of points of failure in the drive and put reliability at risk. HGST needs to be on top of that issue.

Seagate and Toshiba engineers are possibly looking at drives with platters spinning in a helium atmosphere and hoping they could reverse-engineer the technology. HGST is confident that its hard-gained anti-leak smarts will stop them doing that and it has a multi-year advantage opening up. Of course, there will be no second source for helium-filled drives and that might slacken the wind in its sales, and even encourage a technology licensing scheme.

SMR is a stop-gap, an undesirable stop-gap. No-one wants to buy a new generation of disk drives that write data more slowly than the current drives. If helium gas drives delays shingled disks then customers will be all for it, because helium is the write stuff. ®

Reducing security risks from open source software

More from The Register

next story
Sysadmin Day 2014: Quick, there's still time to get the beers in
He walked over the broken glass, killed the thugs... and er... reconnected the cables*
SHOCK and AWS: The fall of Amazon's deflationary cloud
Just as Jeff Bezos did to books and CDs, Amazon's rivals are now doing to it
Amazon Reveals One Weird Trick: A Loss On Almost $20bn In Sales
Investors really hate it: Share price plunge as growth SLOWS in key AWS division
US judge: YES, cops or feds so can slurp an ENTIRE Gmail account
Crooks don't have folders labelled 'drug records', opines NY beak
Auntie remains MYSTIFIED by that weekend BBC iPlayer and website outage
Still doing 'forensics' on the caching layer – Beeb digi wonk
BlackBerry: Toss the server, mate... BES is in the CLOUD now
BlackBerry Enterprise Services takes aim at SMEs - but there's a catch
The triumph of VVOL: Everyone's jumping into bed with VMware
'Bandwagon'? Yes, we're on it and so what, say big dogs
Carbon tax repeal won't see data centre operators cut prices
Rackspace says electricity isn't a major cost, Equinix promises 'no levy'
prev story

Whitepapers

Designing a Defense for Mobile Applications
Learn about the various considerations for defending mobile applications - from the application architecture itself to the myriad testing technologies.
Implementing global e-invoicing with guaranteed legal certainty
Explaining the role local tax compliance plays in successful supply chain management and e-business and how leading global brands are addressing this.
Top 8 considerations to enable and simplify mobility
In this whitepaper learn how to successfully add mobile capabilities simply and cost effectively.
Seven Steps to Software Security
Seven practical steps you can begin to take today to secure your applications and prevent the damages a successful cyber-attack can cause.
Boost IT visibility and business value
How building a great service catalog relieves pressure points and demonstrates the value of IT service management.