/skrach məŋ-kē/
n. As in "Before testing or reconfiguring, always mount a scratch monkey", a proverb used to advise caution when dealing with irreplaceable data or devices. Used to refer to any scratch volume hooked to a computer during any risky operation as a replacement for some precious resource or data that might otherwise get trashed.
This term preserves the memory of Mabel, the Swimming Wonder Monkey, star of a biological research program at the University of Toronto ca. 1986. Mabel was not (so the legend goes) your ordinary monkey; the university had spent years teaching her how to swim, breathing through a regulator, in order to study the effects of different gas mixtures on her physiology. Mabel suffered an untimely demise one day when DEC PMed the PDP-11 controlling her regulator (see also provocative maintenance).
It is recorded that, after calming down an understandably irate customer sufficiently to ascertain the facts of the matter, a DEC troubleshooter called up the field circus manager responsible and asked him sweetly, "Can you swim?"
Not all the consequences to humans were so amusing; the sysop of the machine in question was nearly thrown in jail at the behest of certain clueless droids at the local humane society. The moral is clear: When in doubt, always mount a scratch monkey.