Drive going “haywire” after backups
 

I noticed that my WesternDigital external drive is kicking into overgear once the backup has completed successfully. It keeps spinning and doing stuff for ages, sorting, copying files around, indexing... God knows what. As I’ve been using other sync software before, namely SynchronizePro, where this behavior didn’t occur I was wondering what the drive is doing. Is SuperDuper’s backup function putting the files in such disarray that the drive has to sort them for almost 45 min. thereafter?

Sounds like Spotlight is indexing your backup. Try adding the backup volume into the Spotlight Preference Pane's "Privacy" tab.

Ahh... Spotlight... of course. Thanks for stating the obvious. Stupid me. Will add the drive to the privacy tab.