HDD manufacturers concealed the use of shingled magnetic recording with some disks

Toshiba, Seagate and Western Digital have admitted that some of their hard drives use shingled magnetic recording, without being specified. This technique increases storage density, but can adversely affect I/O performance.

The website Blocks & Files reported earlier this week about Western Digital’s use of SMR without naming it, and then Seagate and Toshiba doing the same with certain HDD models. The companies have admitted to using smr with some hard drives without listing it in the specifications. WD is about Red drives for NAS systems from 2TB to 6TB. With WD Red 8TB to 14TB drives, the company uses cmr, or conventional magnetic recording.

Seagate includes 2TB, 4TB and 8TB Barracuda drives and 6TB and 8TB Archive v2 HDDs. Toshiba concerns P300 desktop drives of 4TB and 6TB and the DT02 models, on which the P300 versions are based. The MQ04 HDDs for laptops also use smr, as does Toshiba’s L200 series based on it.

Blocks & Files was tipped off about WD’s use of smr for the affected Red models by researchers who encountered problems adding such a drive to existing raid arrays. This was due to poor I/O performance on random writes. With shingled magnetic recording, data tracks for writing overlap each other so that more data can be written to the platters. This presents drawbacks with regard to the write speed, which can be partly solved by increasing the cache. SMR disks are less suitable for applications with many random write actions, as can be the case with NAS systems.