Western Electronic has been in warm water for months over its endeavor to provide SMR tough drives into the WD Purple solution family. Purple drives are explicitly meant for NAS (Community Attached Storage) devices, and as we’ve observed in many investigations, SMR drives from WD do not normally carry out adequately in that purpose.
Western Digital’s alternative to the dilemma is to build a new tier of merchandise, dubbed “Red Additionally.” Heading forward, WD Purple will be a three-tiered technique. All SMR tough drives will be marketed as ‘Red,’, when the CMR drives that formerly populated the Purple family will be rebranded as “Red Additionally.” The Purple Pro family will not improve.
Individually, I would’ve preferred keeping CMR (Traditional Magnetic Recording) drives as ‘Red’ and labeling the new SMR drives one thing else, but WD desires to retain the fiction that it hasn’t just bait-and-switched the whole Purple solution family by dumping the onus to master about the big difference on its possess buyer base. Clients who at the moment possess CMR WD Purple drives will have to intuit the need to have to substitute them with Purple Additionally drives when the current types are unsuccessful.
According to WD’s weblog put up on the matter, the travel-managed SMR drives it sells are meant for NAS devices with quite small in general throughput and a wonderful offer of idle time to carry out track record processing. History processing is how SMR drives preserve acceptable general performance when going facts in programmed read/erase cycles, not as opposed to these utilized by SSDs. For a lot more aspects on how SMR drives function, make sure you see our preceding coverage right here and right here.
Western Electronic states this dilemma transpired due to the fact “The explosion of facts observed nowadays has spawned a spectrum of NAS utilizes situations, as well as progressively demanding applications.” I don’t locate this to be an acceptable or credible clarification, and I don’t feel you really should either. The dilemma I have with WD’s statements on this matter is uncomplicated: It’s literally the manufacturers’ position to make certain that its goal-promoted tough drives carry out excellently in the components it is meant to work in. ZFS not actively playing pleasant with SMR is quite significantly a identified dilemma. It just (in some way) was not identified to WD.
WD claims to carry out substantial validation testing on various NAS arrays, which helps make it seem like ZFS configurations could possibly have just fallen through the cracks. But this form of early evaluation is precisely what WD is expected to carry out, and facts from iX Systems — a vendor WD specifically references functioning with on its weblog — shows that WD didn’t carry out that validation method appropriately. From iX Systems:
At minimum one of the WD Purple DM-SMR types (the 4TB WD40EFAX with firmware rev 82.00A82) does have a ZFS compatibility situation which can trigger it to enter a faulty condition less than heavy publish hundreds, including resilvering…
In the faulty condition, the WD Purple DM-SMR travel returns IDNF faults, becomes unusable, and is treated as a travel failure by ZFS. In this condition, facts on that travel can be dropped. Information inside a vdev or pool can be dropped if numerous drives are unsuccessful.
WD has been shipping and delivery these tough drives considering the fact that late 2018. Issues have been stacking up the whole time. What WD seems to have accomplished is to suppose buyers would magically know that their travel-managed SMR implementation experienced troubles with ZFS. There was no notable marketing and advertising substance or steering posted by the company to information persons absent from SMR drives and to CMR if they meant to use ZFS, at minimum not right up until now. There was no specific facts on the dramatic general performance big difference that can arise between SMR and CMR HDDs, as revealed by ServeTheHome:
WD claims to be listening, but states, in the quite subsequent paragraph: “The DMSMR drives satisfied all of our exam specifications.”
The only detail that assertion tells us is that WD’s exam specifications are not thorough plenty of. Telling me “these drives meet up with exam requirements” when the drives are failing in end-person deployments is not a defense, it’s an indictment. It really should be noted that this situation has been assumed to influence all SMR drives in certain NAS arrays. WD is the only company providing SMR drives into these programs, but the firmware challenges iX Systems raises means that some troubles could theoretically be triggered by (or improved by) firmware updates. This seems to be a intricate problem, on the other hand, and the elementary way SMR drives carry out publish functions means they can not match CMR travel general performance in certain duties. Firmware could boost points, but only to a certain level.
I don’t disagree with Western Digital’s declare that SMR drives can cope with some degree of NAS workloads and configurations, but this dilemma really should never have took place in the 1st place. If you intend to use ZFS, you are going to want to get Purple Additionally or Purple Pro drives — or perhaps tough drives from a distinct vendor entirely.