I was wondering if anyone would know of a simple way to omit a large number of volumes from an alert trigger action.
Probably the easiest way would be to include a custom property on the volume (Settings -> All Settings -> Manage Custom Properties). Just create a Yes/No property on volume, and then have that in your alert scope. I would personally go with an Opt out mindset, and create the property as ExcludeVolAlert or something along those lines.
Setting it may take a little bit of time, but you should be able to do that in bulk via Settings -> All Settings ->: Manage Custom Properties, select the new property and then click assign values, then filter however you want.
You could always do the inclusion based on volume name or other custom properties, but pending how your environment is setup, that could be a bit messy.
Ditto. You can use two variations of custom properties - node custom properties and volume custom properties. The node custom properties are great for excluding all volumes with a single property, and you can get very granular when using the volume custom properties. Both cases are yes/no and I agree that it is an opt out. It can be ugly to set up, but this works just fine when its in place.