The concept of switching disk subsystems between servers, all running the same operating system, had become a common and widespread practice on mainframe computers by 1970, and was called "shared DASD" (direct-access storage
See how easily your disaster-recovery vendor can get you more equipment, including things like DASD (direct-access storage
devices), tape drives, and printers.
Low-end models have internal main memory of up to 16MB and up to 945MB of direct-access storage
. "Plug-in-and-go" features allow a system to be installed and running in under two hours.