Toshiba, Seagate shipping slower SMR drives without disclosure, too
tomshardware.com
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Their customers are increasingly likely to be the kind of people who care about this kind of thing.
This doesn't change the fact that enterprise customers are equally screwed by DMSMR drives.
Adding insult to injury is that those disguised SMR (DMSMR) drives were made with very intention to sell "unsalable" SMR drives to Windows users.
* CMR/PMR drives -- Classic hard drive you've been buying for the last 30 years. Not much to say about it.
* SMR Drives -- "Shingled" has very poor write performance, but adds 20% more capacity at lower costs. For "write once, read many" workloads, like archival or backups. This is because "Shingled" drives write data on top of the old data, so that your data is physically overlapping at the microscopic level. Any write must read the old data, rewrite the old data, and then finally write the new data you're planning to store.
* 5400 RPM vs 7200 RPM -- Higher RPM drives are obsolete, because SSDs are faster. 7200 RPM is kind of standard, but 5400 exists for those who want less noise, less electricity usage, and are willing to put up with the lower performance.
That's pretty much it. "NAS" drives tend to have anti-vibration sensors and other such things, but those sensors don't really cost much and I don't really see why it deserves its own category.
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There only needs to be maybe, 3 kinds of hard drives made today. 7200 PMR drives, 5400 PMR drives, and finally 5400 SMR drives.
My backup drive gets written to nightly, but reads are very rare (only in case of data loss).
Low cost write quickly. That is the 5400 coming in but not this.
But the key is to tell us so we can choose. Not as scandal like to get such knowledge and still hiding.
See here:
Looking at the WD Purple drive marketing material... they describe "support for 64 cameras". Which means the CCTV community is willing to pay for write bandwidth. It'd probably be a standard 7200 PMR drive, but with assurances and maybe some tests on the write performance.
It would have to be a highly sequential workload for hard drive performance to not be a problem, but that means it's also a workload that's well-suited for QLC SSDs that are cheaper per GB up front and draw less than half the power and are faster in every way. If your worries about write endurance are at all realistic, you must be averaging upwards of 50MB/s of writes over the entire lifespan of the drive, meaning your hard drives are spending at least 20% of their service life actively writing data.
CMR(conventional magnetic recording) is retronym to differentiate SMR.
Now it's a perfect oligopoly: Seagate, WD, and Toshiba, just like the stories from many other industries.
Anyway, I'd rather data-starve for a couple years and save up for a big SSD rather than feed those responsible for such consumer-hostile practices.
While I was surprised by that figure https://www.seagate.com/ca/en/news/news-archive/seagate-tech... this corroborates, with margin figures indeed roughly 30%-ish.
My favorite idiom comes from China: Pay a lot, cry once.
For the years after that: yes, it seems WD did not want to destroy the high-quality reputation and engineering excellence they paid $4B for.
it has TRIM support
(On that note: if anybody has a disk that supports ZAC or ZBC and wants to get rid of it, I'll happily buy it off of them)
Do you have a reference? Or any evidence of customers knowing or caring about the internals of the drive before this controversy arose?
Claiming that anything is the "best" at something is pure puffery, as we say in the legal trade. Ferrari publishes quantifiable specs on how their vehicles perform; WD does not do so in detail.
I primarily use my NAS for backups and don't care too much about how slow they are, they finish quickly enough.
I just got fucked by this change in models - I had an array full of 6TB WD Reds, had one fail, ordered a replacement. Rebuilding the RAID-Z3 took over 2 weeks. Previous replacements had taken under 2 days - usually under 1.
Passing SMR drives off without saying anything, especially when that exact model had been a PMR drive prior, is incredibly anti-customer.
Then again, drive manufacturers are also known for changing what the definition of a unit of measurement means. Some of us remember when they arbitrarily changed the definition of a gigabyte nearly 20 years ago from 1<<30 bytes to 10^9 bytes - a nearly 7% difference! (See: https://www.zdnet.com/article/attention-hard-drive-manufactu...)
What makes this a sore spot, is that SMR drives have something like 1/8th the sustained write performance of PMR drives.
Think about how you went from HDD world into the SSD world a few years back. Except do that in reverse. SMR drives are great for archives, but they should never be sold as a mainstream solution, because their performance is so much worse than PMR.
You do care about performance - you say so in the next paragraph. In this case, it is rewrite performance. This is quantifiable and can be disclosed on spec sheets and labeling. I'm not saying the recording method can't be disclosed too, but I think to most consumers, the metrics are more important than the technology.
Suddenly, without warning, the "3TB WD Red" is an SMR drive. Technically they changed the model number, but the marketing number (3 TB Red) remained the same.
Do you believe it is reasonable for customers to see this and expect that a drive called "WD 6TB Red" when you purchased previously and when you go to purchase it now, that are described identically, with no way to purchase the previous model, and know that the fundamentals of the storage medium have changed and completely flip it's performance characteristics?
Especially when the drive is specifically marketed as being RAID and NAS friendly - one of the primary differences between the Red and Green drives is disabling some of the sleep power saving mechanisms that are known to cause issues with RAID arrays. And they make it so that the drive is largely unusable in any parity based array? When minor revisions, updated firmware, etc., will result in minor changes to model numbers all the time?
Because, well, I don't.
We're talking about 700% difference in performance. In the case of RAID5, you have many, many physical writes per OS-level write. If you have 5-hard drives storing 100MBs, you'll need to actually write 120MBs to disk.
On the SSD side we have DRAMless and TLC.
The annoying thing is that unless the government forces disclosure, the honest manufacturers are the ones hurt, having to start advertising "no SMR!" to differentiate, like the organic/health food products in the grocery store that have to list all the poisons they don't have.
I'm happy to buy a DRAMless + TLC SSD for my boot disk on my web browsing PC (not development), it is a reasonable compromise for a lower price. Same for SMR drives, I won't have problems with them as backup disks.
I think the problem here is SMR drives are sold without disclosure, and it has already created some serious problems in practice.
> What’s worse, they’re shipping DM-SMR drives as “RAID” and “NAS” drives This is causing MAJOR problems – such as the latest iteration of WD REDs (WDx0EFAX replacing WDx0EFRX) being unable to be used for rebuilding RAID[56] or ZFS RAIDZ sets: They rebuiild for a while (1-2 hours), then throw errors and get kicked out of the set.
I don't doubt it, but do you have the source for that? I read stories about people using the Seagate Archive disks in RAIDZ and it worked fine for them.
This has accelerated my move to enterprise 16TB drives, because I really don't want to expose myself to data loss on rebuilds taking hugely extended times.
This also means you'll need a lot more HD's per RAID set to guard against multiple failures during rebuild. Which means that even the supposed data density/space advantage of SMR is moot - you'd be better off with PMR.
* Western Digital admits 2TB-6TB WD Red NAS drives use shingled magnetic recording
https://blocksandfiles.com/2020/04/14/wd-red-nas-drives-shin...
Are you sure you're not talking about QLC? Current TLC drives can be pretty decent in terms of write speed and endurance.
Some workloads will never have a problem, others will hit performance walls.
Of course, for NAS RAID arrays that were already saturated by TLC man times over, it makes little difference.
Depending on how you define average, yes. But a sufficiently bursty workload is always writing to SLC. How the drive performs in practice depends on where you sit on that spectrum.
Explaining: there are 100% TLC drives high in the benchmarks, as long as you look at 1tb+ category.
You only need 3 times more chips with TLC than MLC, which was still easily doable, and there were no equivalent sized MLC chips anyways.
Read speeds weren't a problem with any flash technology, but QLC will give you harddrive level read speeds at sizes below 1tb.
QLC will only take off in SSD's sized 5TB+ if per-chip speed will not improve dramatically, like at least twofold.
QLC + huge cache is not good deal cost wise in comparison to pure TLC.
Speed-wise no, but it (almost) keeps up with the lower end of TLC NVMe drives.
> QLC + huge cache is not good deal cost wise in comparison to pure TLC.
Cost wise? Yes it seems to, Sabrent's "Rocket Q" is about the cheapest 2TB on the market, and performs pretty well, Reads more or less competitively with the non-QLC drives from the same vendor and writes at around 2/3 the speed.
Intel's 660p range performs a little less well, but typically still multiple times as fast as SATA drives, and is generally cheaper too.
I've tried QLC drives for cheap cluster storage. It turns out one QLC drive was slower than 4 old HDDs. I had to go back to HDDs until I switched to TLC flash because they were faster. Tail latencies hitting one second on QLC. It's incredible how bad they are. We shouldn't even be calling them SSDs at that point, they don't even remotely live up to the performance expectations you might have from an SSD.
This doesn't come out in tests or consumer experience of the drives that have a significant cache, like the aforementioned "Rocket Q", which has a DRAM cache and a large SLC/TLC cache behind it.
Cluster storage is not a mainstream consumer use.
> We shouldn't even be calling them SSDs at that point
Is the intel 660p range not an SSD? It significantly outperforms SATA SSDs.
Was that a consumer QLC drive with SLC cache or an enterprise QLC drive with no cache and firmware that actually cares about latency? Something like the Micron 5210 ION enterprise QLC drive should still have at least 20x the sustained random write performance of a single hard drive.
Also, "boost the main muggle"? I usually think I know my Potter references, but this one escapes me.
TLC and QLC are misnomers, a TLC cell holds 3 bits but has eight levels and QLC likewise 4 bits with 16 levels. You get a multiplicative increase in capacity for an exponential decrease in reliability. The manufacturers have been very obfuscatory with the marketing, since they know the inconvenient truth.
Does anyone still make a reasonably large (>100GB) SSD with good old 100K SLC? I have a 64MB (true 2^26 bytes capacity!) flash drive with 100K SLC; 0 bad blocks when it was new, and still 0 bad blocks a decade and a half later despite plenty of abuse.
To go a bit further, I'm amazed you don't see a drive manufacturer offering an enterprise-client "firmware builder" tool, or at least as a build-to-order service if you're a big enough client. I could see customers that wanted to respec their 1TB drives as, say, 750GB to ensure an abundance of over-capacity for reallocation later, or the YOLO "I'm gonna run the cheapest drives in RAID0" crowd slashing overprovisioning and getting 1050Gb out of the same unit. If you dialed down the capacity low enough, the drive could presumably stay in "use SLC mode only" mode for its entire duration.
I'm amazed you don't see a drive manufacturer offering an enterprise-client "firmware builder" tool, or at least as a build-to-order service if you're a big enough client.
If they do, you probably wouldn't hear about it --- and I suspect they do, given that there are things like this: https://superuser.com/questions/593303/hitachi-hard-drive-wi...
Or at least that's the theory.
I'd want the drive statistics or benchmarks to include a complete rebuild process, though.
That said, you would want to use a log structured filesystem, with a compaction feature. You want to avoid read-modify-write on the shingled areas, it's time intesive and competes with other I/O.
Yes, nothing except extremely low load or extremely linear (i.e., security video / tape-style backup) workflows works well with drive-managed SMR.
The SATA/SCSI spec, together with operating systems, block device interfaces, and filesystems, would all need to be updated to have more parameters to correctly handle SMR drives properly. Since hard drives are going out of fashion and architectural changes like that will take 5+ years to be widely deployed, it's never going to happen.
SCSI and SATA and operating systems already have support for host-managed SMR — the name used in this context is "ZONE" and those changes happened around 5+ years ago.
If a zone is empty, and you try to write sequentially to it, I would sure hope the firmware isn't so hopelessly dumb as to redirect that data to a staging area.
This does require that they don't disable TRIM support, I guess.
I'd really like to see some detailed analysis of how these drives perform.
But the point I'm making is that "host-aware" should be good enough for this type of use. Even though it's still drive-managed, the internal logic in the drive should pass through certain write patterns without interference. And you can make the host aware through feeding in a few parameters; it doesn't necessarily have to interrogate the drive.
In other words, I'm disagreeing with the idea that this big laundry list of things would need to be updated. The filesystem should be sufficient if these drives act in a way that's at all reasonable.
The thing is you can't really buy SMR disks that are OS controlled unless you are some big enterprise client.
SMR disks discussed here are DM-SMR disks, which basically are same disks, but with a firmware based hack that makes them appear as regular SATA disks.
But I wonder if folks are better off buying host managed or host aware drives instead, and pairing it with either dm-zoned and their preferred file system; or a file system that supports ZBC and ZAC natively (Btrfs does, I'm not sure about others).
Note that dm-zoned has significant changes starting with kernel 5.5.
Not really, no. SMR drives overlays data on top of each other, like "shingles" on a typical American roof.
As such, whenever an SMR drive writes data, it must read the data "underneath" the current spot, rewrite the "underneath" data, and then lay the new data on top of it.
SMR drives are great for archives (write once, read many). But they're pretty much useless to the typical consumer. SMR drives should be avoided if you're building your own computer.
WD Blue drives had SMR / Shingles in them. WD Green drives were shoddy, low quality, and had issues with RAID Rebuilds. WD Red commanded a high price, but came with higher quality.
What's happened here, is that WD has begun to sell low-performance drives under their high-priced "Red" brand.
Isn't that the wrong way around? Archives are write many, read maybe. I do regular backups that I hope I never have to read.
SMR performs generally fine except in the physical rewrite case. A 6TB disk is unlikely to see a lot of physical rewrites except in this pathological case of a RAID rebuild that people are complaining about.
Perhaps all the data you care is on the cloud, but HDDs are still important for backups. Although it's the most acceptable scenario to use an inferior SMR disk. The real issue of SMR is RAID/servers, which, of course, is what the cloud is made of...
What if you connect your hard-drive and the data is corrupted or the drive isn't spinning? That did happen to me. I rather have people replacing the hard drives for me. Uploading corrupted backups to the cloud is the same than saving corrupted backups locally.
Or any bulk data storage, really.
That's my point. I said I don't see myself needing HDDs again. Unfortunately hn read that as me saying nobody ever needs HDDs again :/
I've got about 3TB of SSD space and gigabit internet. That leaves me with very little need for massive NAS space, but others might.