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Toshiba, Seagate shipping slower SMR drives without disclosure, too

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Re: Toshiba, Seagate shipping slower SMR drives without disclosure, too

#51
post #29
post #19

Earlier quoted context omitted.

Yeah. QLC is bad but mature TLC with a DRAM cache can be an excellent choice b

QLC with a decent SLC cache seems to work just fine as well, for most consumer purposes - see drives like the sabrent Rocket-Q

QLC with SLC cache is probably the best analogy for these drives, too.

Some workloads will never have a problem, others will hit performance walls.

Re: Toshiba, Seagate shipping slower SMR drives without disclosure, too

#52
post #46
post #42

Earlier quoted context omitted.

You don't need a single Log structure -- the shingle stripes are on the order of 128 MB of or so. Any CoW filesystem can relatively easily adapt to this kind of system; in-place filesystems are basically boned on SMR. The CoW filesystem aren't going to be fast on SMR, mind you, just not quite as awful.

Except filesystems like ZFS are having issues on these SMR Reds during resilvers (rebuilds) because SMR slows down so much.

"Can relatively easily adapt" is not the same as "has already been adapted". It still performs awfully without the work put in to make the hardware and software cooperate, but doing that work is not nearly as big of a burden.

Re: Toshiba, Seagate shipping slower SMR drives without disclosure, too

#53
post #47

Trying to pass SMR as PMR is kind of pointless since HDD becomes more and more pro and enterprise territory and consumer are shifting away to SSD. Their customers are increasingly likely to be the kind of people who care about this kind of thing.

> pro and enterprise territory 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.

I read parent as saying that trying to cut corners with SMR is even more stupid seeing that the HDD-market is becoming 'more enterprise' on average.

Re: Toshiba, Seagate shipping slower SMR drives without disclosure, too

#54
post #29
post #19

Earlier quoted context omitted.

Yeah. QLC is bad but mature TLC with a DRAM cache can be an excellent choice b

QLC with a decent SLC cache seems to work just fine as well, for most consumer purposes - see drives like the sabrent Rocket-Q

You need 6 times more QLC chips to get an equivalent write performance to TLC on average.

Of course, for NAS RAID arrays that were already saturated by TLC man times over, it makes little difference.

Re: Toshiba, Seagate shipping slower SMR drives without disclosure, too

#55
post #54
post #29

Earlier quoted context omitted.

QLC with a decent SLC cache seems to work just fine as well, for most consumer purposes - see drives like the sabrent Rocket-Q

You need 6 times more QLC chips to get an equivalent write performance to TLC on average. Of course, for NAS RAID arrays that were already saturated by TLC man times over, it makes little difference.

> You need 6 times more QLC chips to get an equivalent write performance to TLC on average.

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.

Re: Toshiba, Seagate shipping slower SMR drives without disclosure, too

#56
The annoying part about all this is that I want to buy some SMR disks (HM ideally, but HA will do) to experiment with storage tech. I know that there are lots of devices out there that are SMR internally, but because of vendors hiding the information, I can't actually buy what I want.

(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)

Re: Toshiba, Seagate shipping slower SMR drives without disclosure, too

#57
post #53
post #47

Earlier quoted context omitted.

> pro and enterprise territory 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.

I read parent as saying that trying to cut corners with SMR is even more stupid seeing that the HDD-market is becoming 'more enterprise' on average.

SMR drives have more of a place in the enterprise market than the consumer market, just like tape drives. Enterprise/datacenter customers tend to have a much better understanding of their workloads and are more able to determine when they have a use case for niche technologies. They also have a greater ability to deploy tiered storage with SSDs in front of hard drives to cover up the performance limitations.

Re: Toshiba, Seagate shipping slower SMR drives without disclosure, too

#58
post #56

The annoying part about all this is that I want to buy some SMR disks (HM ideally, but HA will do) to experiment with storage tech. I know that there are lots of devices out there that are SMR internally, but because of vendors hiding the information, I can't actually buy what I want. (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)

Google the exact drive name and SMR. People have started to put together lists.

Re: Toshiba, Seagate shipping slower SMR drives without disclosure, too

#59

Earlier quoted context omitted.

> WD Red drives were de facto marketed as PMR 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.

SMR is terrible for NAS setups, particularly RAID5. Absolutely terrible. Under no circumstances should you be putting an SMR drive into your NAS.

Isn't this a question of throughput? What is the bandwidth of SMR and what workloads can't it support that PMR can?

I primarily use my NAS for backups and don't care too much about how slow they are, they finish quickly enough.

Re: Toshiba, Seagate shipping slower SMR drives without disclosure, too

#60

Adding to this confusing debacle is how HDDs are now being marketed like running shoes: one type for running, one for squash, one for tennis, one for basketball...

There are only maybe... 3 or 4 elements of HDD designs worth talking about. * 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,…

I don't know if there's any truth to this, but I've read NAS drives also declare themselves "bad" much more readily through SMART, so you replace them sooner.
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