My photos collection has way over 500 gigabytes, and when I got a new Mac in 2015, I moved the collection to an external hard drive, and pointed Photos (iphoto by then?) to the external hard drive.
So far, so good. Everything works most of the time, with all the known glitches of Photos which are covered in many other questions.
My question is regarding disk usage. My hard drive is being used 100% of the time (and quite loudly), since 2015. The thing NEVER stops.
I have spotlight disabled for that hard drive, and the people search doesn't show anything anymore (like that "X images still need to be scanned).
The processes using the hard drive are
filecoordinationd(4 threads, same PID)
com.apple.MediaLibraryService(also 4 threads, 1 pid)
If I kill all those processes, I end up with
fseventsd in 1 thread, 28 threads of
photoanalysisd, 1 thread of
mds, and 4 threads of
revisiond. It quiets things for a while, and the activity comes back after a while.
Why is this happening and how to fix it? Again, this is bothering me for FIVE YEARS. It's not something temporary.