With its 16TB and 18TB EAMR Hard Disk Drives already available, Western Digital is sampling a new 20TB SMR drive that’s expected to hit stores soon.
The Energy Assisted Magnetic Recording (EAMR), used in the 16TB and 18TB models, is Western Digital’s chosen approach for storing data storage on large HDDs. EAMR applies electricity to the HDD’s recording heads to correct their jitter. This leads to more consistent data writing on the disk’s surface, allowing for denser storage.
Technologies like EAMR and Heat Assisted Magnetic Recording (HAMR) are the primary reasons for the large storage capacities in the latest HDDs. Together with Shingled Magnetic Recording (SMR), they take different paths for upgrading traditional magnetic recording.
SMR drives were at the epicenter of a minor havoc recently
Western Digital was accused of mislabeling and pushing SMR HDDs to servers for which they were far from optimal.
SMR drives split the disk surface into zones of a predefined size that depends on the drive’s capacity and firmware. The problem with SMR is that if only a small part of such a zone changes, the whole area must be read, updated, and re-written. This reading-updating-re-writing can happen consistently on server setups or when the drives are set in RAID arrays, with the result being a significant drop in performance, or in worst-case scenarios, full hardware failure.
We hope EAMR and HAMR, chosen by Western Digital and Seagate as the way forward for large capacity HDDs, won’t come with similar “bugs.”