Optimizing Spotlight for Better Performance

Spotlight can interrupt important work, suck up CPU time, and generally make a nuisance of itself at inconvenient times. But you can still benefit from Spotlight, yet be less annoyed with it.

Exclude backup volumes, scratch volumes, Time Machine volume

Imagine making a formal presentation to your boss, and suddenly having the Mac become herky-jerky— the Windows PC users will start to snicker!

Or simply trying to get everyday work done: Spotlight can be exceedingly useful for finding items you know you have, but Apple has done nothing to make its behavior understandable and controllable— beyond the ken of most users (the Spotlight process for example is the obtusely-named “mds”).

Exclude folders or volumes that do not want indexed and searchable by dragging them to Spotlight’s Privacy panel as show below.

Be sure to exclude backup volumes, Photoshop scratch volumes, and in most cases your Time Machine volume, unless you have a very good reason for wanting to search them. You can always unexclude them at any time.

Backup interference

Suppose a large backup is in progress (I regularly backup 1.6TB of data onto an external backup). I never want the backup volume indexed by Spotlight — it’s pointless.

Spotlight might decide to start indexing the backup volume while the backup is in progress, causing a huge slowdown in backup speed (doubling or even quadrupling the required time, not to mention sucking up CPU time).

The solution? Exclude all backup volumes, and remember that after erasing a drive, you’ll have to re-exclude it; Spotlight has the temerity to forget about the excluded volume once it’s erased, even if the name remains the same.