Dear Aunt TUAW: Locating Missing Versions and Files

Dear Aunt TUAW,

Hello, I’ve stumbled upon what appears to be a glitch in the new “Versions” feature of Lion. When I modify an image saved on my desktop and then exit Preview, the changes are saved automatically. Reopening the file allows me to revert to the original version without issues. However, when performing the same actions on an image stored on a USB drive, attempting to revert to the original version results in a message stating “No previous version available” and “Time Machine can’t find your backup disk.”

This is quite problematic.

Any edits made to images on the USB drive have to be manually reversed before closing the file to avoid saving the changes. Is this a common issue, or is it just happening on my system?

Your loving nephew,


Dear Romesh,

The “Versions” feature does not function on non-HFS+ formatted drives. It seems the issue is with the format of your USB drive.

Typically, Lion stores versions of your documents in the .DocumentRevisions-V100 folder on HFS+ formatted drives. When you work on a file stored on a non-supported drive, Lion discards any temporary versions upon closing the document, which is why you can’t revert to them later.

You might consider reformatting your USB drive to HFS+ using Disk Utility.

Check out the directions in this post for detailed instructions on how to do this. Once reformatted, your drive should support versioning in Lion, and Preview will be able to access previous versions of your files.

Additionally, using HFS+ allows you to utilize FileVault to encrypt your drive, enhancing the security of your data should the drive be lost or stolen.

Below, I’ve included some additional insights into versioning for those who are interested.


Auntie T.

The Document Interaction Control Menu

Here are some lesser-known facts about versioning. You’ve likely noticed the drop-down menu that appears next to the file name in the title bar, which looks like this when accessed.

Did you know that by holding down the option key while in the “Browse All Versions” view, you can change the “Restore” button to “Restore a Copy”? This allows you to keep both the current and previous versions of the document.

Furthermore, the document interaction menu is also available within the version browser itself. By clicking to the right of each file name in the history stack, you can access options to manage your document’s versions.

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Jennifer is a dedicated writer for TUAW, bringing a wealth of knowledge and enthusiasm to the world of Apple news. With a deep love for all things Apple, Jennifer covers everything from the latest iPhone and iPad releases to the newest features in macOS and watchOS. Her insightful articles and engaging style make complex tech topics accessible to everyone. Jennifer’s expertise and genuine interest in Apple products shine through in every piece she writes, making her a valued member of the TUAW team.