These files can be created even when users just browse a windows volume, and while they may be invisible to Macintosh users, Windows users will see them created all over the place.

DS_Store Files Beyond the creation of resource fork files, OS X is notorious for cluttering windows-formatted volumes with other hidden files, such as trash folders and the irritating '.DS_Store' files which hold folder-specific settings. Therefore Apple has built a file-handling mechanism into OS X which automatically splits the resource and data forks into two files when copied to disks that do not support resource forks. As such, when users copy files to these systems the resource fork can be lost. In Mac OS X filesystems these forks are treated as one file, and appear as such however, resource forks are not supported on many filesystems, including those used on Windows machines (SMB and NTFS). The data fork will contain user-supplied information such as the text of a word document, and the resource fork will contain information about the document such as author, document-specific preferences, and other metadata. In Macintosh filesystems (HFS and HFS ) there is support for two types of file information: one is the resource fork, and the other is the data fork. '._' Files These invisible files are 'resource fork' segments of files that are being created on the external volume. This causes problems, for example, when I copy music files to an mp3 player, it tries to play the invisible file and reports an error which is very annoying.' 'Whenever I copy files to external windows formatted disks, a duplicate invisible file with prefix. For the most part these files wont cause problems, but in some instances they can interfere with some functionality.Īpple Discussions poster Doug Rostad writes: When users copy files to some destinations other than the boot drive, they might get multiple files created, some of which can be invisible for some operating systems but visible in others.

Osx duplicate file cleaner