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It's a small but annoying glitch I'm experiencing. A recent convert from Win so there may be some Finder preference I'm not aware of?


  1. I plug my portable drive (500GB formatted as FAT32).
  2. Browse to a movie folder in Finder - List mode. Finder slowly caches all the video thumbnails (well, except for ogg but that's normal :-)
  3. I disconnect my portable drive.
  4. Reconnect the drive and browse to the same folder.
  5. All thumbnails are gone, Finder goes about recreating them.

Any ideas on how to solve this issue?

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lists in this markdown need to be separated from the preceeding paragraph by a blank line. ftfy. :) – quack quixote Jun 11 '10 at 19:31
Ah, I see! Thanks for correcting that & the explanation, the first and last time I make this error :-) – Dav Jun 13 '10 at 17:28
up vote 1 down vote accepted

Thumbnails are typically stored in an HFS+ resource fork and are "invisible" to the end-user. However, since FAT32 doesn't have forks (and by OS X not wanting to be like Windows and make a Thumbs.db file in every single folder), it has to regenerate the thumbnails every time you plug the hard drive in.

Simple explanation: OS X can't store the thumbnails in the resource fork so it opts not to save them on disk at all.

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If there is such a thing as a perfect answer, the above would be a member of the club. Thanks for answering, a detailed explanation and sharing your knowledge! – Dav Jun 13 '10 at 17:31
@Dav No worries! Glad I could help :) – squircle Jun 13 '10 at 18:31

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