Stop Spotlight from Indexing Your Time Machine Backup 

So that I can find this again some day.

I plugged my Time Machine drive in to backup my laptop today (at work, my offsite backup). I couldn’t eject it once it was done. After a bit of research, seemed like it was stuck with Spotlight indexing the drive, even though I have Spotlight set to ignore the drive.

After some googling, found this on Stack Exchange:

sudo launchctl unload -w /System/Library/LaunchDaemons/com.apple.metadata.mds.plist

Running that stopped Spotlight, and allowed me to eject my disk. Running

sudo launchctl load -w /System/Library/LaunchDaemons/com.apple.metadata.mds.plist

started Spotlight back up again normally.

Still not sure why Spotlight ignored me telling it to not index the backup disk, but that’s a different problem.