HGST’s 10TB drive uses custom software to access shingled platters
HGST first revealed its 10TB cold storage drive back in September. The 3.5" mechanical unit combines helium-filled internals with Shingled Magnetic Recording (SMR) to hit a new capacity milestone, and it's finally ready for prime time. Customers will start getting production drives in a couple of weeks. The Ultrastar Archive Ha10 won't be available through conventional channels, so don't expect it to hit online retailers. HGST's host-managed SMR implementation requires substantial customization on the software side.
SMR crams more data onto the platters by overlapping the individual tracks like rows of shingles on a roof. This layering is typically managed by the drive, without host-level intervention. That approach is great for compatibility, but according to HGST, it can result in inconsistent performance and dramatic slowdowns over time. The firm claims its host-managed solution can smooth out those wrinkles with custom software.
The simplest path to SMR support involves "large modifications" to the storage driver and block layer. SMR hooks can also be integrated into the file system and applications. That's all possible in Linux now with an open-source SDK available on Github. HGST also expects some native driver and file system support for host-managed SMR by late 2016, but only for server platforms. Archival drives aren't meant for consumers.
The Ultrastar Archive Ha10 is derived from HGST's Ultrastar He8, an 8TB drive based on traditional perpendicular recording tech. It inherits the He8's helium-filled internals—and the thinner platters and reduced power consumption made possible by helium's lower density. Seven platters are stacked inside the chassis, and perhaps more impressively, they rotate at 7,200 RPM. Don't expect impressive performance, though. Compared to He8's 205MB/s sequential specs, the Ha10's 157MB/s read rate and 68MB/s write speed are plodding at best and crawling at worst.
Slower write speeds are inherent to shingled recording, limiting the technology's appeal to archival environments that only write data once. More specifically, the Ha10 is targeted at active archives, where data is read frequently at first and less so over time—think social media and online storage rather than a replacement for tape-based archival backups. The big "hyperscale" customers in HGST's sights already run custom software, so they shouldn't be fazed by the coding requirements attached to host-managed SMR.
Unlike some archival alternatives, the Ha10 comes with an enterprise-class five-year warranty. HGST claims the drive has a better load/unload tolerance, lower error rate, and higher MTBF spec than the competition, which isn't too shabby for a product that also happens to offer more storage.