Western Digital Launches 20 TB NAS HDD with 64 GB iNAND

[TheLostSwede]

Although 20 TB hard drives aren't a new thing by now, Western Digital's latest drive for NAS appliances are doing things a bit differently by incorporating WD's OptiNAND technology. The WD Red Pro family is Western Digital's higher-end family of NAS drives and have a generally good reputation in the market. The drive is made up out of nine ePMR (energy-assisted perpendicular magnetic recording) platters, each coming in at 2.2 TB. As with the previously launched drives in the Red Pro family, we're looking at a 7,200 rpm drive with a SATA 6 Gbps interface. The internal transfer rate is said to reach up to 268 MB/s which makes it the second fastest drive in the series, just behind the 18 TB version.

What makes the 20 TB SKU unique in the Red Pro series though is the inclusion of 64 GB of WD's own iNAND flash. Western Digital's iNAND could be considered a DRAM-less SSD in a single chip package and in this case, it's used as a large chunk of cache for the hard drive. One other benefit of the OptiNAND technology according to WD is that up to 100 MB of data in the 512 MB DRAM write cache that the drive also has, can be flushed to the iNAND in case of an unexpected power cut to the drive. This could help save important data that is in transit during a worst case scenario and seems like a great addition to a hard drive that's targeting NAS applications. The WD Red Pro 20 TB is on sale now for US$499.99.



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[Chaitanya]

Eagerly waiting for review and hopefully there are smaller capacity(10TB) drives with iNand. On flipside given this is WD not sure whether to trust them with both Warranty handling and bait and switch.

 

[Ferrum Master]

And how this PMR + caching is RAIDable as NAS disk driver where it is a norm?? I guess mirror only?

 

[TheLostSwede]

And how this PMR + caching is RAIDable as NAS disk driver where it is a norm?? I guess mirror only?

Western Digital Reimagines HDD - Flash Integration with OptiNAND

www.anandtech.com

 

[Ferrum Master]

Western Digital Reimagines HDD - Flash Integration with OptiNAND

www.anandtech.com

It would take years for Linux filesystems to be aware of such drives and utilize them correctly. The idea remains same. SOHO should use only PMR based NAS drives if they utilize RAID features. I won't even guess how cleaning sync jobs, data rot will act with these.

 

[Valantar]

Hm, these look nice, though there's no way I could afford two of them for a NAS upgrade. If I did it would probably last me a decade in terms of capacity though! I wonder if the NAND allows the platters to spin down while keeping frequently used data available - that would be pretty cool for my use case at least, which is mostly semi-cold storage. Definitely hoping this tech will trickle down into smaller capacities too.

 

[ncrs]

Apparently those 20TB drivers are rated for only 300TB/year of workload (which is read and writes in WD terminology), which seems very low...

 

[Valantar]

Apparently those 20TB drivers are rated for only 300TB/year of workload (which is read and writes in WD terminology), which seems very low...

That's rather weird. I guess most NAS users don't need 15 yearly full-drive writes for a 20TB drive, but that's nonetheless a pretty low number. And of course one that can easily be exceeded if you've got the right/wrong workload. I guess WD wants those people to buy a different product line?

 

[Ferrum Master]

That's rather weird. I guess most NAS users don't need 15 yearly full-drive writes for a 20TB drive, but that's nonetheless a pretty low number. And of course one that can easily be exceeded if you've got the right/wrong workload. I guess WD wants those people to buy a different product line?

Instead they mishmash same series drives with different technologies, making a headache often to pickup up the right ones. It is like erasing claims for exact RPM rate. For example some drives are not 5400 or 7200 anymore. They gimp on anything they can and offer us some gimmick with a premium price.

 

[bobsled]

That’s a lot of data to lose at once. And forget about a timely RAID rebuild!

 

[chodaboy19]

I'd love to see some benchmark, very exciting product!

 

[Valantar]

That’s a lot of data to lose at once. And forget about a timely RAID rebuild!

Now imagine a storage server rack filled with hundreds of them

 

[Chaitanya]

Out of curiosity tried to look up detailed datasheet and seems like WD is hiding data on their drives and these inand drives arent even on their website properly. Atleast with Seagate I can find manuals on product page(for each SKU) itself which covers all the minute details of drive.

 

[Valantar]

Out of curiosity tried to look up detailed datasheet and seems like WD is hiding data on their drives and these inand drives arent even on their website properly. Atleast with Seagate I can find manuals on product page(for each SKU) itself which covers all the minute details of drive.

They probably just don't want to be too clear about all the drives being the same, just with different coloured stickers and firmware locks

 

[Chaitanya]

They probably just don't want to be too clear about all the drives being the same, just with different coloured stickers and firmware locks

Also hiding specs means it easier to switch for lower quality parts in future and no one notices.

 

[kapone32]

How are these different than Seagate's SSHDs? Is not the base technology the same. 64GB is nice though. I wonder if we will see these in 2.5 form factor. This could potentially be great for Mass Game storage.

 

[Chaitanya]

How are these different than Seagate's SSHDs? Is not the base technology the same. 64GB is nice though. I wonder if we will see these in 2.5 form factor. This could potentially be great for Mass Game storage.

How Western Digital Created OptiNAND

The promising new architecture uses flash to improve performance, reliability, and increases drive capacity.

blog.westerndigital.com

https://documents.westerndigital.com/content/dam/doc-library/en_us/assets/public/western-digital/collateral/tech-brief/tech-brief-reimagining-hdds-with-optinand-technology.pdf

 

[kapone32]

How Western Digital Created OptiNAND

The promising new architecture uses flash to improve performance, reliability, and increases drive capacity.

blog.westerndigital.com

https://documents.westerndigital.com/content/dam/doc-library/en_us/assets/public/western-digital/collateral/tech-brief/tech-brief-reimagining-hdds-with-optinand-technology.pdf

I just read that article and I guess the main difference is Seagate has software to run the SSD and HDD (And RAM) and this comes with a physical controller chip. I want to see a 5TB with the 64GB just to see how it performs vs the Seagate in my own benchmarks.

 

[TheUn4seen]

Seems like the SSHD from a few years back. Oh my, what horrible, proprietary rubbish those were. Useless in a NAS because they were randomly spinning up due to some cache purging shenanigans, which caused them to die prematurely. One can only hope these are better.

 

[Valantar]

I just read that article and I guess the main difference is Seagate has software to run the SSD and HDD (And RAM) and this comes with a physical controller chip. I want to see a 5TB with the 64GB just to see how it performs vs the Seagate in my own benchmarks.

From my skimming of that, I don't agree with your take. First off, they explicitly say that it isn't a hybrid drive - which of course begs the question of how the architecture actually works, but seems to indicate that this isn't a "slow HDD with a small amount of fast persistent cache for frequently accessed files" type of setup. The only caching mentioned that I could see was write caching, which seems to be optional (can be turned on or off). Other than that, literally the only use for the flash I see mentioned is storage of (massive amounts of?) metadata, allowing the drive to use these to store tracks closer together, refresh smaller portions of tracks rather than whole tracks, and other advanced, low-level drive operations. I'm struggling to imagine even this depth of metadata necessitating a whopping 64GB of space, but I guess there's some overprovisioning involved, plus space for that optional write cache? Either way, this seems to be rather different (and more specialized) than an SSHD.

 

[kapone32]

From my skimming of that, I don't agree with your take. First off, they explicitly say that it isn't a hybrid drive - which of course begs the question of how the architecture actually works, but seems to indicate that this isn't a "slow HDD with a small amount of fast persistent cache for frequently accessed files" type of setup. The only caching mentioned that I could see was write caching, which seems to be optional (can be turned on or off). Other than that, literally the only use for the flash I see mentioned is storage of (massive amounts of?) metadata, allowing the drive to use these to store tracks closer together, refresh smaller portions of tracks rather than whole tracks, and other advanced, low-level drive operations. I'm struggling to imagine even this depth of metadata necessitating a whopping 64GB of space, but I guess there's some overprovisioning involved, plus space for that optional write cache? Either way, this seems to be rather different (and more specialized) than an SSHD.

Does the drive not have 64GB of Flash? If there are spinning disks along with the flash attached to the PCB by definition it is a Hybrid drive (Regardless of what they say). The same thing could be said about AMD's SSD/HDD software (that they bought) that did the same thing. Having a physical controller is the mitigating factor that makes all the accoutrements that you are describing very interesting from an enthusiast stand point.

 

[Valantar]

Does the drive not have 64GB of Flash? If there are spinning disks along with the flash attached to the PCB by definition it is a Hybrid drive (Regardless of what they say). The same thing could be said about AMD's SSD/HDD software (that they bought) that did the same thing. Having a physical controller is the mitigating factor that makes all the accoutrements that you are describing very interesting from an enthusiast stand point.

SSHDs also have a controller - it's just (AFAIK) integrated into the HDD controller. You literally can't use flash without a controller.

As for the rest, you're missing the point: they're saying that what makes a hybrid drive isn't what it is (an enclosure with a HDD+significant amount of flash), but what it does with those components. SSHDs typically use that flash as a R/W cache, with a focus on reads for frequently accessed files (system files etc.). StoreMI works in much the same way, though with even broader read caching. There is literally zero mention of such functionality concerning this drive, so it does seem that it works in a way that is quite different. I completely understand what you mean by saying that it's still a hybrid drive - it does still combine two storage technologies, after all - but barring that this WD blog post turns out to be just BS, there does seem to be a meaningful distinction here. If this entirely lacks read caching functionality, that is a very significant difference.

 

[chrcoluk]

I think there is a merit for this type of drive, but my issue is the proprietry nature. Something like SSD caching in a HDD ZFS pool I think is better, but of course thats more expensive in both $$ and i/o slots/bays.

I last used a hybrid drive in my PS4 (seagate, still own it, its in a sdd box now), and it worked ok'ish, I remember tales of vesperia eventually hit SSD levels of performance about the 3rd or 4th time I played an area. No internal counters I think to measure erase cycles etc. on the nand.

 

[lexluthermiester]

Apparently those 20TB drivers are rated for only 300TB/year of workload (which is read and writes in WD terminology), which seems very low...

Are you kidding? Do you have any idea how much 300TB is? That's ALOT of data. Most drives in a NAS will never get close to that estimated(key word) limit, read or write.

 

[ncrs]

Are you kidding? Do you have any idea how much 300TB is? That's ALOT of data. Most drives in a NAS will never get close to that estimated(key word) limit, read or write.

I am not kidding, 300TB is only 15 times the capacity.
Keep in mind that what WD means by workload: it's both writes and reads.
The drive is rated for 268MB/s so it only takes 311h to hit this workload limit. There are 8760 or 8784 hours in a year - WD uses the former. So unless my math is incorrect, it means that this HDD is only rated for 3,6% of a year. That's barely 13 days.
If you're fine with that for a drive having "Pro" in the name then be my guest.
Take into account specialized filesystems, often used in NAS or servers, like ZFS or Ceph which can have write amplification in order to keep the stored data secure. They also scrub all the data on regular intervals, so expect a lot of spurious reads.