I’ve had terrible issues with Mac OS X never completing Spotlight indexing and Time Machine backups. I was pulling out my hair until I decided to check the console log. That’s when I saw this: Thousands of mdworker errors, with a dozen appearing every second. What could it mean?
There was no more information in the console or inspector. I immediately turned to the Google and found some suggestions that ExFAT was at fault.
I love ExFAT. It’s a great filesystem for removable media since it’s readable and writable on both Mac OS X and Windows and scales gracefully with today’s larger storage devices.
But Mac OS X apparently does not love ExFAT. Specifically, it appears that mdworker, the background task used by both Spotlight and Time Machine, chokes on ExFAT volumes. This is the source of the “bad path” error: Mdworker seems to continually retry doing something with ExFAT volumes. And mdworker never stops.
I’m not sure how to fix this issue, though I can offer a suggestion to help: Eject any ExFAT volumes before initiating a Time Machine backup or Spotlight indexing run. For me, this immediately halted the mdworker warnings and allowed Spotlight to complete its work.
Note: This issue appeared in November 2013 in Mac OS X 10.9 “Mavericks”. Let’s hope Apple fixes it in the future.