Prevent partitions from Spotlight indexing each other I have a single MacBook Pro partitioned into two drives, each running a copy of Mountain Lion. In Partition X, I would like to disable Spotlight from indexing Partition Y. In Partition Y, I want to disable Spotlight indexing of Partition X.

Clarification:

Under System Preferences > Spotlight > Privacy, setting Partition X to prevent indexing of Partition Y also prevents Partition Y from indexing Partition Y. I.e., the privacy settings are preserved across partitions. I am looking for unique privacy settings for each partition.
System Preferences.. &gt; Spotlight &gt; Privacy
Add the mount path you don't want indexed to the list by selecting the device you want excluded also. However, if it's hidden use ⌘ +⇧+G and enter the path name for example /Volumes/Partition Y.


Note
After some testing this method does not work with multiple partitions of like OSs (eg. 10.8 on partition A and 10.8 on partition B) but does seem to work if each OS is different. Still not 100% clear on why this is since each drive has it's own /.Spotlight-V100/VolumeConfiguration.plist or /.Spotlight-V100/Store-V1/Exclusions.plist