Problem copying files

They are "metadata" and/or "resource forks." The former, which also includes any .DS_Store files, store information about the file, such as its position in the window in the Finder, comments, label colors, etc.

Resource forks, which would be one thing stored in the ._Filename files, are additional file data stored in a different way in the filesystem. In the WAY back era, many files had resource forks that were an integral part of what they stored. OSX has moved strongly away from them, such that I no longer know of any modern app that creates files with anything in the resource fork.

If you had a file with a necessary resource fork, deleting the ._file would essentially break it. In practice, most current stuff has nothing useful there, so deleting those files might remove some Finder info, but the file is 100% fine.

On network volumes there is a (hidden) preference to stop the creation of .DS_Store files, but this doesn't help with USB drives and such. I know of no way to stop their creation, but there are a number of apps, some free, that will automatically delete them for you; try searching on VersionTracker.com or MacUpdate.com for DS_Store or "invisible files" or something of the sort, and poke through what you get.

As above, there are a number of utilities, some free, that will tell the Finder to show invisible files. Invisibility Toggler is one, and I believe the popular Cocktail can do this, too.

 

._files ghost files show up on Win Server

I have a windows server with all PC's running happily together. A mac user recently joined the team and we were having issues with duplicated ghost ._files showing up on our server. The mac could not see these files only the PC users could see them.

Yes you can always turn these off (don't show hidden files using Explorer) but this does not resolve the issue.

The solution we found - thought I would share as I spend 2 days trying to find and answer and it seems that a lot of people have the same issue. It through software called Dave.

http://www.thursby.com/products/dave.html

This resolved the problem right away.

I'm not sure at this stage this there is a free way to do this ... if I find it I will be sure to post. But if you are running a business and need to resolve this issue it may just be worth spending the $ (about $170 for 1 year with tech support and upgrade capabilities).

Hope that helps someone out there with the same issue.