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New Seagate Shingled Hard Drive Teardown
New submitter Peter Desnoyers writes: Shingled Magnetic Recording (SMR) drives are starting to hit the market, promising larger drives without heroic (and expensive) measures such as helium fill, but at a cost — data can no longer be over-written in place, requiring SSD-like algorithms to handle random writes.
At the USENIX File and Storage Technologies conference in February, researchers from Northeastern University (disclaimer — I'm one of them) dissected shingled drive performance both figuratively and literally, using both micro-benchmarks and a window cut in the drive to uncover the secrets of Seagate's first line of publicly-available SMR drives.
TL;DR: It's a pretty good desktop drive — with write cache enabled (the default for non-server setups) and an intermittent workload it performs quite well, handling bursts of random writes (up to a few tens of GB total) far faster than a conventional drive — but only if it has long powered-on idle periods for garbage collection. Reads and large writes run at about the same speed as on a conventional drive, and at $280 it costs less than a pair of decent 4TB drives. For heavily-loaded server applications, though, you might want to wait for the next generation. Here are a couple videos (in 16x slow motion) showing the drive in action — sequential read after deliberately fragmenting the drive, and a few thousand random writes.
At the USENIX File and Storage Technologies conference in February, researchers from Northeastern University (disclaimer — I'm one of them) dissected shingled drive performance both figuratively and literally, using both micro-benchmarks and a window cut in the drive to uncover the secrets of Seagate's first line of publicly-available SMR drives.
TL;DR: It's a pretty good desktop drive — with write cache enabled (the default for non-server setups) and an intermittent workload it performs quite well, handling bursts of random writes (up to a few tens of GB total) far faster than a conventional drive — but only if it has long powered-on idle periods for garbage collection. Reads and large writes run at about the same speed as on a conventional drive, and at $280 it costs less than a pair of decent 4TB drives. For heavily-loaded server applications, though, you might want to wait for the next generation. Here are a couple videos (in 16x slow motion) showing the drive in action — sequential read after deliberately fragmenting the drive, and a few thousand random writes.
Oh look here are some SSD optimised file systems already. Incidentally they apply to these drives rather well.
The main downside is the disk becoming much more algorithmically complex (read: bug-prone) for a less than a radical improvement in performance.
The real question is whether or not Seagate can maintain similar full drive performance compared to a non-SMR drive.
No.The real question is longevity. Per backblaze and my own anecdotal experience, Seagate drives already have a higher failure rate. Looking at this, any firmware bug or flaw could result in massive data loss of an entire 'band' if written incorrectly.
I understand that in any environment backups are crucial, but I live in the real world. A world where small and medium size business (for good or ill) neglect IT until it bites them. At least with regular drives recovery is often possible with block for block copies, and baring that a clean room has a good chance of recovering crucial data.
If a user has a performance need, I can suggest an SSD or SSD+HDD config with appropriate redundancy and backups. For pure space, large HDDs in an appropriate RAID or ZFS work fine. Per TFS, this is not ready for heavily drive loaded server configs yet, and i do not see a need in residential, or small biz or workstation use where other solutions are far better. To me this is currently a product looking for a solution, and one that is risky to data to boot.
Silence is a state of mime.
Why not just go full SSD?
For much the same reason we still use tape. Sometimes read/write speed isn't nearly as important as $/TB.
Drive performance is kind of like airplane legroom - people gripe about it, but in the end they ignore it and buy the cheap ticket.
Shingled drives aren't better - they're bigger, and that's what people pay for. WD's 10TB helium drive is shingled, and I would guess that every drive over 10TB will be shingled for the foreseeable future. By the time HAMR and BPM come out, SSDs will probably have killed off the high-performance drive market, so those technologies will probably be released as capacity-optimized shingled drives, too.
No tapes, we just have another data center like this one and a big ol pipe and XYZ data backup solution attached to the disks at the other end."
So, you're not protected against malicious destruction of data? Pretty sure that requires an air gap.
Grammer Nazis - I mod you "troll" unless you actually add something on-topic. Yes, I know I have mispellings in my sig.