 Tommy here for more systems and Western Digital admits 2TB to 6TB WD red NAS drives use shingle magnetic recording. And there's going to be some more updates to this article, I'm sure. This is what it stands right here on April 18th of 2020. So if you want to learn more about me and my company, head over to LawrenceSystems.com. If you'd like to hire short projectors, a hires button up at the top. If you want to support this channel and other ways from affiliate links down below to get your deals and discounts on products and services we talk about on this channel. Western Digital, what are you doing here? These are NAS drives. You shouldn't be using SMR. Alright, let's start with what's SMR and why is it something you shouldn't use in a NAS system. So this is a great article over at Blocks and Files. I'm not going to read all of it, but we'll cover the basics. So Blocks and Files, can you contrast conventional magnetic recording and the SMR rate process, the shingled one? And what they show here is this is the goal to get more and more data on the tracks. How do you do that? Get the tracks closer together? Well, they can only go so close, but maybe they can go closer if you did something a little bit different. It turns out if the blue represents the right tracks and the read track is in red, so you have to push more to write, but less to read it. So I can read a narrower track, but to get that track laid down is wider. This is kind of a neat way that it's exploited and it's referred to as shingling or shingled overlapping tracks. So what they do instead of leaving enough distance between them, they overlap the tracks a little bit. This is rather clever, but the way this has to work. Essentially, unlike conventional drives, an SMR drive puts a lot of logic and distance between the interface and the actual platter. It's far more like an SSD in many ways, only much slower. SMR disks have multiple levels of caching, DRAM, then some CMR zones, so they do some conventional writing, and finally the shingled zones. In general, right to the CMR space, and then the right, when the disk is idle, the drive will rearrange itself in a background, tossing the CMR data onto shingled areas. There might be 10 to 200 shingled zones. They're all open, appendable, like SSD blocks are. If a sector within a zone needs changing, the entire zone must be rewritten in the same way and SSD blocks and zones can be marked and discarded as trimmed the same way SSD blocks are. It's an important sentence, and you can read all the other details to dive into some of these, but obviously where the concerns are is the pause and delays that occur. Now, these work fine in terms of cold storage. Like, I want to dump a bunch of videos to a single drive and have them sit there. This is a good use case for SMR, where SMR fails is an arrayed system. That fact that you have to reread the block, throw it up into cache, and rewrite it back causes problems. Now the drives are kind of a mix of CMR and SMR. So you're thinking probably those right to CMR, and it rearranges in the background. That's great when you have enough space as these drives fill up. So if you have a rate array, and you have a lot of data on there, and one of those drives fails, that's where everything goes wrong. What it's going to do is start pausing it more and more, trying to do that rearranging in the background, because it's got to get the data over to a shingled area for better storage, and find the time to do the writing on the CMR with a drive kind of working as much as it can, as hard as it can. And the way a rate array gets rebuilt or resilvered when one drive goes bad and you replace it, is it starts building parity, kind of like in a random poll order almost, and starts rebuilding all these tiny little reads and writes to reassemble it. Well, if it starts pausing a lot, the rate array, whatever's managing it, ZFS, or in there's more than one device are talking about here, Synology has issues with this as well, really any type of rate system is going to go, nope, I don't know why this drive is pausing, it must be bad, and now your drive may or may not get rebuilt, or it'll get rebuilt at an extremely slow pace. So this is obviously of great concern to people who built these rate arrays, and why they should have never been used as a NAS drive. And there's some double talk going on with the folks over at Western Digital, and trying to figure out which ones, for example, this note here, just a quick note, only the only, this is from Western Digital, SMR drive that Western Digital will have in production, our 20 terabyte enterprise hard drives, and even those will not be rolled out into the channel. All of our current range of hard drives are based on CMR, conventional magnetic recording, except for the brochure says right here, this is an UltraStar HC620, and it says right here, SHR drive and key features, SMR, they're telling you, it's on the drive. So Western Digital is either misinformed, confusing, or just some double talk because when they see in the channel, they may be referring to something very specific. And then of course, Western Digital also says they're usual of, we plan to support our customers and we think these drives are fine, but there's enough discussion and there's enough things going on to try to figure out what the real issue is, dive into it and sort it out. So here's the Synology Forum links, I'll leave a link to this because there's a lot of different discussion forums that they kind of jump back and forth between so you can dive into and figure out which ones might be affected, if yours is affected, if it's risked or not. And it does sound like, and this is this article has been updated to include some other companies that may be doing it as well. And it's going to really take a lot of people over on the SMART mon to try to determine what the commonalities on these drives are to determine it. And why isn't it just a flag? Well, let's dive into that a little bit. So what happens is the SMART mon utilities is not like these companies, Western Digital or really any drive company gives us these wonderfully clear maps that are drives. No, doesn't work that way, generally a lot of reverse engineering to try to determine what a flag means. And how do you even find that information? Well, you find that information by running a smart control and pointing it at one of the drives. This happens to be a free NAS system I have set up. And we just dumped all the data out of the drive that SMART mon can see. And what you have is device or vendor specific log device or vendor specific log. There's different addresses that they pull from to read these things out. Some things are easy and they understand what ID number matching it to this drive and understand what these things mean so they can convert it to information. There's some things they do not have documentation for to convert information. So they go over here and people open up a ticket. And what do we do with that ticket? Well, we have to make some termination of what is it about those drives that has to be found to determine which ones have it. So I could just, you know, include it as a smart function. And this is where the problem lies. All rotational drives with trim support or SMR drives. So that seems like a really easy way to do it. I'll just run the smart tool. And if I find that the drive has trim support, and it's a rotational drive because trim is needed on SSDs for another reason outside of the scope of this discussion. But rotational drive shouldn't need trim. Well, they can use trim. They need trim in order for SMR to work. However, not all SMR drives exposed the trim function. That's where the hang up is right now. So they're trying to determine, like, if there's a flag, if there's a code set on each one of these, because what they're doing is the controller is hiding from you that it's actually using trim. So if you have one, we're not positive or maybe there's not a flag that hasn't been discovered yet that will let people know that they have one of these particular drives and it will solve that mystery of I bought a brand new drive. Why wouldn't it rebuild, which is of course the indicator that some people have been poking around at and complaining about in forums, but not really getting good answers for. So now there's a lot of discussion here. I'll leave a link to this as well, where you can dive into see what drives people have to make some termination. There's more tickets being open where people are dumping, you know, their drive information. And this is really helpful to the developers in the community because what happens is the community, maybe you're a developer working in the working on the smart man tools and writing some of the code for this, maybe you don't have one of every hard drive laying around because it's just not within your reach to grasp all of those. So it's always helpful if you want to join in and help people if they're looking for certain models, maybe you have one of these and you can contribute meaningfully to some of these conversations. That's great. If you're looking for solutions, there's not right now any, you know, one off easy solution for this is something that is still being developed is something that is still obviously being truly tried to determine what other solutions are might be for this. The easy solution, at least from a standpoint of replacing a drive sounds easy, except for the fact that you have X monofamina server. And that does not necessarily work out to a good cost benefit. You bought these already with the word NAS written on them expecting them to work. And now Western Digital is essentially admitting, yeah, that sounds like some of these might be SMR and it should be fine. It's kind of like Western Digital had another statement of we'll stand behind our customers product and blah, blah, blah. All of our WD red drives are designed to meter exceed performance requirements. So allegedly, that's what they're supposed to do for common small business home NAS workloads. And we will work closely with all major NAS providers to ensure WD red HDs and SDs have at all capabilities are broadly compatible with host systems. So we'll have to see wait and see what happens from this, whether not Western Digital offers people replacements, whether or not which drives really have SMR, and whether or not we're going to be able to reliably determine on any of these spinning drives, if that's the issue. And there's a few other things that you can find a few links. I don't know any of the models besides Western Digital or if these are companies reached out for comment. But as of right now, the census articles published, Seagate and Toshiba have also confirmed undocumented use of shielded metting recorded in some of their drives. But I don't really know, we can click on these, but I don't know that they really have clear answers into it. But there's some links, of course, you can do a little more reading on this Toshiba desktop drive still have shingles to do some reading, hopefully you don't have any of these drives if you do, if they're working awesome. But something to keep in the back of your mind, if you have to replace any of them, look and be careful which models replace because a re-silvering process of adding that new drive if you used one of these drives to re-silver on it could cause you a lot of drama and a lot of untold hours of headache trying to figure out why your radar won't rebuild. Thanks. 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