Sometimes you don't want your Spotlight to index some parts of your Mac, e.g. your backup drive. If that's the case, you can set up your Spotlight to prevent searching in several locations. This setting can be performed under
System Preferences ▸ Spotlight ▸ Privacy. Adding that particular folder into the pane provided will result in Spotlight stop indexing that folder.
If you want Spotlight to reindex a certain volume, you can use following terminal line :
sudo mdutil -E -p "/Volumes/Mac HD"
Note : The volume name
Mac HD is just for example, you should change it accordingly to the drive you want Spotlight to reindex.
Some articles taken from our resource base, tightly related to current article, to empower you with more knowledge on tweaking the most out of your Mac.