According to the Avid ProTools 10.0.1 update documentation dated Jan 18, 2012:
Spotlight indexing can interfere with long record passes (97151)
There are known incompatibilities with Spotlight indexing drives while recording audio. If you will be recording to a large number of tracks for over an hour, set all of your drives to private in the Mac OS X System Preferences to ensure maximum performance. Failure to do this may result in Pro Tools reporting an error and ending the record pass when Spotlight indexes the drives.
It took me a few minutes to figure out how to do this, so let me save you the time. Screen shots are from Lion.
In System Preferences, you should see Spotlight toward the right of the top row.
In the Spotlight preference area, click the Privacy tab.
Click the “+” on the lower left and choose a record drive.
The OS will display this warning. Click OK.
You will see the selected drive on the Privacy list. Continue this process with any/all record drives.
Please note that you wouldn’t want to actually prevent indexing of your system drive as shown here; this is merely for example. You wouldn’t want to record to your system drive either.
See the full Avid document here-
@kylepsnyder made an excellent point about the example shown above: do not disable indexing for the system drive. He also advised that Spotlight indexing, Time Machine and much more can be managed using Cocktail. Cost: $19.
If you want more tips for making your Mac great for audio work, be sure to read OSX Optimization for Audio by Jon Tidey (@theaudiogeek). It is a great companion article to this one whether you use ProTools or something else.
Side note: in my opinion Finder and Spotlight have become less and less useful for finding files. Allow me to recommend EasyFind instead. It’s great and it’s free.
See also: ProTools + H.264 video = Problem, ProTools Sync: The Short Video Problem