Blocks and Files We've seen a lot of innovation in disk drive technology over the past year or so, tech into which millions of dollars of R&D as well as large amounts of time and effort have been poured. But from where we're standing at the beginning of 2014, it may ultimately be totally useless for storage array vendors.
I'm thinking of breakthroughs such as shingled magnetic recording (SMR), using Ethernet as the access protocol (as in Seagate's Kinetic drives, for example ), and helium-filled drives (such as HGST's) and asking myself why Dell, EMC, HDS, HP, IBM, NetApp and every other traditional disk storage array vendor would wish to use them.
Take shingling: its write performance is abysmal because of the need to rewrite a band of tracks whenever as much as a single byte of data is rewritten. We've heard that WD is supplying SMR drives to Facebook and Seagate supplying them to its subsidiary EVault, but why would any general storage array vendor want to take on drives with abysmal write performance?
We're hearing that SMR drives are more susceptible to vibration-induced failures, making them good for spin-down, archiving applications. That indicates they can't be added to general-purpose disk arrays because they'll fail more often.
Seagate's Kinetic drives present an object storage interface using an Ethernet connection, and are intended to have server-based software driving them. Seagate's idea is to radically simplify the number of layers in the application-to-disk drive access stack, cutting out traditional storage array controllers for one.
As if that is not enough, any storage array using them will have major software interface work to do. Also, with just a single supplier (Seagate) from which to source them, why should they bother?
Array vendors like dual-sourcing disk drives so that if one manufacturer's supply runs into problems they can switch to another. The Thai floods demonstrated the need for that flexibility.
This is what could kill the appeal of helium-filled drives. They only come from HGST and no other source is available. Even if an array supplier does get a drive capacity jump from using them, they will soon become totally dependent on HGST for an uninterrupted supply. That risk could kill helium drive tech prospects for the array vendors.
The general disk array vendors want a pretty much plug-in successor to current PMR drive tech when it runs out of oomph and that means HAMR (Heat-Assisted Magnetic Recording). For EMC, Dell et al, shingling, Ethernetting and helium-filling are sideshows. When all you have is a disk array nail then what you need is a HAMR. ®