SMR allows vendors to offer higher capacity without the need to fundamentally change the underlying recording technology. While the vast majority of the Seagate BarraCuda 2.5" 4 TB HDDs will use a four-platter configuration, some Seagate customers have apparently requested a five-platter configuration. Obviously, being based on 800 GB platters, such drives have lower areal density and, perhaps, different performance and behavior. All 2-6TB external drives - Elements, My Book, Easystore, etc. Precise models vary and are not guaranteed; assume SMR in capacities below 8TB.

Seagate presents the BarraCuda, an extremely versatile and reliable HDD storage device that provides ample space for all types of files. Ideally, the disk can be used in laptops, mobile storage, external storage systems, all-in-one PCs, or ultra-thin desktop PCs. Especially useful is the multi-tier caching technology used, which allows applications and files to load faster than ever from the HDD. Responsible for this are intelligent NAND flash levels, DRAM and media cache technologies, which optimize the data flow and improve the reading and writing performance. WD platter sizes 2.5": https://rml527.blogspot.com/2010/10/hdd-platter-database-western-digital-25.html

Versatile, Fast and Dependable.

Host Aware, HA-SMR, which is designed to give ZFS insight into the SMR process. Note that ZFS code to use HA-SMR does not appear to exist. Without that code, a HA-SMR drive behaves like a DM-SMR drive where ZFS is concerned. When it comes to data recovery one of the most common problems Seagate ST2000LM015 Hard Disk Drive experience is burnt circuit board(PCB). So if you will need to match a replacement PCB, it is important that you note the “ Board Number” of your current circuit board in addition to the hard drive’s “ Model Number“. Seagate platter sizes 2.5": https://rml527.blogspot.com/2010/09/hdd-platter-database-seagate-25.html

Anandtech lists Seagate 2.5" Barracuda as SMR: https://www.anandtech.com/show/1075...5-mobile-hard-drives-with-up-to-5-tb-capacity The BarraCuda is very economical, compact, quiet and at the same time extremely fast, even in comparison with many HDDs from other manufacturers.Toshiba platter sizes 2.5": https://rml527.blogspot.com/2010/09/hdd-platter-database-toshiba-25.html