Show processes that block umount

Another quick one: I forget this command on a permanent basis, so I write this down here – maybe this helps.

$ lsof +f -- /media/mountpoint

Update on 2021-11-21 #

You could also use fuser. I prefer this one because somehow I cannot use autocompletion with lsof and fuser lets me complete the paths.

$ fuser -vm /media/mountpoint