June 9, 201511 yr TechReport has a writeup on the 10TB HGST drive: http://techreport.com/news/28426/hgst-10tb-drive-uses-custom-software-to-access-shingled-platters They indicate that there is software driver modifications made for Linux to be able to properly support the shingled media. At this point, seeing how well Seagate has done without custom software and managing it from a firmware perspective, I'm quite disappointed in the HGST drive from a conceptual level. 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.
June 9, 201511 yr Well, you wont be able to buy these through NewEgg and Amazon anyway. So, most of us will never see one. I'm waiting for the 8TB helium drives to fall below $500 before I start buying.
June 11, 201511 yr Important thing to note with these 10TB drives, they're host managed SMR. That means they don't act like a normal drive the way the Seagate Archive SMR drives, which are device managed. The HGST drives will need fancy file system management running on the server. I believe linux does support it in some way, but I don't know how. So even if you could buy the HGST 10TB, you wouldn't be able to use it on UnRAID.
June 11, 201511 yr Yes, that's definitely an important distinction. Basically host-managed SMR allows for higher areal density, since there's no persistent cache on the drive, and the drive is effectively one large shingled band. There are disadvantages ... no overwrites, can't start writes anywhere except the current write pointer location, etc. => but for large, high-density storage akin to magnetic tape these work very well and can have very high areal density (thus they can already get 10TB on a drive). There's a good overview in this paper from Seagate: http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=4&ved=0CEwQFjADahUKEwj4-P-I0ojGAhVJIqwKHV4QAPE&url=http%3A%2F%2Fwww.snia.org%2Fsites%2Fdefault%2Ffiles%2FDunn-Feldman_SNIA_Tutorial_Shingled_Magnetic_Recording-r7_Final.pdf&ei=JwV6VbjJBsnEsAXeoICIDw&usg=AFQjCNHAZKGGWvvXWsZ5O7KUc9qcW2r5zw&bvm=bv.95277229,d.b2w
June 11, 201511 yr Basically host-managed SMR allows for higher areal density, Allows for, perhaps, but the 10TB does not achieve higher density. It is only 25% increase from the 8TB drive it is based on. The Seagate 8TB is 33% higher than the 6TB it is based on. since there's no persistent cache on the drive, and the drive is effectively one large shingled band. There are still many bands, more importantly, there are several writable zones. The host can use a zone for persistent cache. ie "host managed" persistent cache. There are disadvantages ... no overwrites, can't start writes anywhere except the current write pointer location, The write pointer can be reset. The data is then overwritten. etc. => but for large, high-density storage akin to magnetic tape these work very well and can have very high areal density (thus they can already get 10TB on a drive). Tape density is still magnitudes beyond disk density, and the gap is widening.
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