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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.
One thing I've tended to wonder, why have a single read-write needle on conventional drives (especially in multi-platter situations). Why not have two needles, one on either side so they can't touch.
Alternately, why not a "track" that runs across the drive with shuttles on either side to perform the reads/writes. You could have two perpendicular tracks to increase performance
... except in some cases where these filesystems make some wrong assumptions about the wear leveling mechanism below and perform worse than a generic, disk-oriented fs.
The main downside is the disk becoming much more algorithmically complex (read: bug-prone) for a less than a radical improvement in performance.
The 8 TB drive is the one being priced.
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.
Because that's worked so well for the seagate hybrid drives. (hint: no it doesn't)
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.
Find me an 8TB SSD that is even within spitting disttance (hell, within ICBM distance) of $300 and you win the prize, otherwise the suggestion is sless. Hint: Not today, not next year. Possibly this decade . The cost has come down a ton, but it was absolutely astronomical before.
The systems I'm buying now will be obsolete by the time SSD can even think about touching hard drives in terms of capacity per $. Typically, the ONLY reason to go full SSD now for large storage capacities is because you absolutely need the performance and are willing to pay essentially "whatever it costs" (at least 8x+ the price) because it's that important to get the IOPS. Maybe by the end of next year we'll get it down to "only" 4x the price (not counting that though because price per GB for large capacity hard drives still continutes to fall, balancing out a part of the cost reduction in SSDs).
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.
I've worked for multiple Fortune 500 companies. All used spinning tape. And nearly everywhere I've worked has used tape. It's cheaper and easier to buy tapes. You sound like a salesman, but I've never seen the numbers work for an off-site storage, Tapes are cheaper than hard drive storage, and more controlable (having them physically stored where you want, restoring only what you want, good for lawsuits).
Learn to love Alaska
There is even ransomware out there that exploits domain privs and actually attacks Active Directory to encrypt schema and the user information, which would shut an entire organization down.
All users should be a member of the Domain Users group along with other security groups isolated to the share access they need. Only IT sysadmin should be using AD accounts that are Domain Administraors and Schema for utilitarian reasons only! Even sysadmins should have their own Domain Users AD account. Sadly, many sysadmins still conflate the roles with one account; very bad!!
Life is not for the lazy.
How impatient must one be to tear down a Seagate hard drive before it breaks down?
Who still uses tape? Seriously, no data centric company on the planet still uses tape, its easier and cheaper to throw a bunch of large drives and a big fat pipe to offsite storage than deal with a tape robot.
People still using tape are doing so because they haven't moved on and like pain or are just ignorant of the alternatives.
Google, probably the most "data centric" company on earth, that's who!
http://highscalability.com/blo...
http://www.theregister.co.uk/2...
Andy Warhol got it right / Everybody gets the limelight
Andy Warhol got it wrong / Fifteen minutes is too long.
There are several solutions that take an SSD and hard drive and present one logical drive to the OS.
Windows: Intel Smart Response
OS X: Fusion Drive
Linux: bcache/flashcache
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.