[Blue Spirit]

WD Sets the Record Straight: Lists All Drives That Use Slower SMR Tech

https://www.tomshardware.com/news/wd...smr-techNOLOGY

Network-Attached Storage or NAS devices have become critical for homes and small businesses that need to find a larger and more reliable storage solution.
These often use high-capacity, high-speed hard drives in RAIDs (Redundant Array of Independent Disks) for data reliability and integrity.
Imagine the surprise, then, of some NAS users when their favorite brand’s NAS drive starts to behave poorly in such a RAID setup.

The culprit, it turns out, is the technology known as Shingled Magnetic Recording or SMR.
Unlike Conventional Magnetic Recording (CMR), SMR overlaps tracks a bit when writing data to a platter, creating a structure that resembles the shingles on a roof, hence the name.
The compact structure is great for increasing the capacity of a hard drive but it comes at the cost of performance.
You can only read and write on SMR drives sequentially because you can’t write to a track underneath another without potentially damaging the data on the upper track.

That makes SMR drives a poor choice for RAIDs where random access I/O is more the norm.
Unfortunately, a report from the Blocks and Files site reveals that Western Digital’s Red NAS drive is actually using SMR even if it doesn’t state it in any documentation.
WD isn’t the only culprit, though, as both Seagate as well as Toshiba also later admitted some of their drives marketed for NAS use employ a technique that is known to be bad for NAS use.

None of these three HDD makers find anything wrong with the little white lies. They basically claim that what they explicitly advertise and document is “consistent” with the drives’ performance. NAS users, however, might beg to differ.

https://www.slashgear.com/wd-seagate...yers-17617133/