Why restoring from a Mac to another operating system sometimes corrupts files (4047310)

Date: 10/2006
NV Version: N/A
OS Version: N/A
Application version: N/A
Plugin version: N/A

Description:
An overview about the nature of Mac files and the caveats when restoring to other operating systems

Symptoms:
When restoring files from a backup that had been performed on a Mac to another operating system, some files might appear corrupted - i.e. cannot be opened by the relevant programs on Windows, and even when copied back to the Mac are different

Mac files (even on OS X) contain two forks on HFS and HFS+ file systems: The data and the resource fork. Comparing the original file that is stored on the Mac and the restored file on Windows shows that the Windows file is larger, and header and tail contain a chunk of extra data. This data is the resource fork that has been restored as if it was part of the main file, because our filesystem plugin for example on Windows doesn't know about this concept.

There is an existing fault FSG-137 for this, but due to the nature of the Windows and some other file systems (especially FAT), this feature of Mac files probably can't be implemented. All the plugin could do in this case is warn.

The only solution for this is to restore files containing resource forks back to the operating system they came from - the Mac OS.