Coined by Data General back in its heyday, memory sniffing is a diagnostic routine that tests memory during normal processing. The processor uses cycle stealing techniques that allow it to test memory during unused machine cycles. A memory bank can be "sniffed" every few minutes. See
Data General.
Memory Sniffing
Sniffing a memory bank may not look exactly like this, but it does the job of testing memory while the computer is processing the daily work.