How to prevent Spotlight from Indexing Backup Drives?

[minckster]

gryphonent, I have an idea on what the problem may be, as I had difficulty getting shell scripts to run with scheduled backups too. After you add the shell scripts to your advanced options, you have to recreate your scheduled backups for them to "stick" as part of the scheduled activity.

Edit to add: Ooops! I just noticed that you mentioned that the shell script did indeed run after the backup. Never mind! My next wild-a$s guess is some sort of problem passing a parameter from SD to the shell script. It's a simple one:

#!/bin/sh
echo "Disabling spotlight for $4..."
mdutil -E -i off "$4"