Just hours into using my new 27-inch iMac with 32GB of memory, the system felt sluggish. I checked memory usage via the
top -u command in Terminal, which showed all 32GB was full. Exclamation point, I said aloud, and launched Activity Monitor to dig in more easily than at the command line.
Sure enough, all memory was in use, and the culprit was something I’d never seen before: com.apple.MediaLibraryService. Turns out that this service relies on Apple plug-ins to make music and other audio, photos and video, and GarageBand files available throughout macOS, including via the options in the Media section of the Open dialog box’s sidebar.