OS X Server: When saving files on SMB shares, the permissions may be changed so only the owner can read or write
Products Affected
Lion Server, OS X Server (Mountain Lion)
Symptoms
Files saved on an SMB sharepoint may have group access removed when you save them.
This can happen when applications use "safe save," which is used to minimize data loss if the save process is interrupted. The process creates an updated copy of the file that will replace the old file. That way, if the process is interrupted, the previous version of the file remains intact. As a consequence, the saved file is created as a new file with default access permissions which only allow the owner to access the file. Users who are part of a group that had access to the old file will not have access to the newly saved file.
Resolution
Turn on ACLs on the server and configure ACL inheritance on the share to save the group access.