"磁盘存储器" can be translated as "disk storage" or "magnetic disk storage" in English.
"Disk storage" is a more general and commonly used term that refers to any storage device that uses disks (such as hard disk drives or floppy disks) to store data.
"Magnetic disk storage" specifically emphasizes the magnetic technology used in the storage process, which is a characteristic feature of many traditional disk storage devices.
In most contexts, "disk storage" would be sufficient and more widely recognized.