Spotlight index of mounted volumes
From Tech-Wiki
Spotlight index of mounted volumes: (maybe ignored by macos though?)
mdutil -i on /Volumes/nameofvolume | Enables Spotlight indexing mdutil -i off /Volumes/nameofvolume | Disables Spotlight indexing mdutil -s /Volumes/nameofvolume | Displays current status of indexing mdutil -E /Volumes/nameofvolume | Erases the Spotlight Index