Western Digital uses almost every spot in its 22 TB drive for storage. However, the fastest media zone is not on the outer edge of the panes.
Hard drives are being replaced by SSDs in many areas. However, when it comes to storage space that is as cheap as possible, as in the server cabinets of Facebook, Google and Co., then hard drives are still better off. The three remaining manufacturers use their capacity-increasing developments primarily in server hard drives.
Western Digital has the only 22 TB hard drive with conventional recording technology in its range to date, the Ultrastar DC HC570. The technical data in brief: SATA or SAS connection, 10 magnetic discs and 20 read/write heads, helium filling for reduced friction, 7200 revolutions per minute and Energy Enhanced PMR, ePMR for short. The manufacturer puts the probability of failure at a common 0.35 percent per year, and the workload rating at 550 TB per year.
There is 64 GB of flash memory on the circuit board, in which the drive’s firmware stores various metadata – Western Digital calls the technology OptiNAND. At the same time, the flash memory also serves as a write cache, in which the data is safe in the event of a power failure, unlike in a DRAM cache. Administrators can therefore safely enable the cache to speed up applications.
