A standalone dump is the copying of the contents of computer main storage (random access memory) to another storage device, usually for the purpose of debugging a programming problem. (An earlier, now out-of-date term is core dump.) The term is primarily used in the mainframe environment. When an IBM mainframe stops operating because of a "hard wait state" or a "machine check" condition, an operator or system programmer can perform a "Store Status" operation that saves the program status word (PSW) and the 16 general purpose registers (GPRs), which tell exactly what the computer was doing when it stopped operating, and then performs a standalone dump to copy real and virtual memory to tape or direct access storage device (disk storage). These operations are performed from a system master console. After an initial program load (IPL) to restart the operating system, the standalone dump can be formatted by a special utility program and printed or displayed. Diagnostic techniques can be used to isolate the failing component so that ultimately the customer can get a fix from IBM or report a new problem.
When a mainframe operator encounters "hard stop" errors in the middle of the night and calls the system programmer, the advice is often to "Take a standalone dump and call me in the morning."