Which filesystems are compatible with both Mac and PC and support extended file attributes

Question

I have an external hard drive that I'd like to use with both Mac and Windows. I want to avoid the ._ file issue (see Removing ._ Files from Non-Mac OS File System In Dropbox)

What filesystem can I format the HD to that supports extended file attributes (and thus avoid the ._ files) and is compatible with both Mac and Windows without use of additional drivers or whatever?

I know there are a ton of questions about filesystems for sharing among Mac/PC. I specifically want to know which are compatible but additionally support extended file attributes.

Thanks

score 1 · Accepted Answer · answered Mar 01 '18 at 17:03

Nothing meets all your criteria. The only filesystems macOS reads and writes out of the box without doing the ._ AppleDouble files are the Apple-proprietary HFS+ and APFS filesystem families. Windows does not read and write either of those filesystems out of the box.

score 0 · Answer 2 · edited Jun 12 '20 at 13:48

The macOS operating system includes the dot_clean command, which can be used to remove the dot files from a FAT32 or ExFAT formatted drive partition. I consider the work needed to periodically run this command is about the same as emptying the trash.

For example, if my external drive is named MYEXTUSB, then I could use the command shown below to remove the dot files.

dot_clean /Volumes/MYEXTUSB

Appendix

The dot_clean man page from macOS 10.13.3 (High Sierra) is given below.

DOT_CLEAN(1)              BSD General Commands Manual             DOT_CLEAN(1)
NAME
     dot_clean -- Merge ._* files with corresponding native files.
SYNOPSIS
     dot_clean [-fmnsv] [--keep=[mostrecent|dotbar|native]] [dir ...]
DESCRIPTION
     For each dir, dot_clean recursively merges all .* files with their cor-
     responding native files according to the rules specified with the given
     arguments.  By default, if there is an attribute on the native file that
     is also present in the . file, the most recent attribute will be used.
 If no operands are given, a usage message is output.  If more than one
 directory is given, directories are merged in the order in which they are
 specified.


OPTIONS
     -f      Flat merge.  Do not recursively merge all directories in the
             given dir.  This is off by default.
 -h      Help. Prints verbose usage message.

 -m      Always delete dot underbar files.

 -n      Delete dot underbar file if there is no matching native file.

 -s      Follow symbolic links.  This will follow symbolic dot underbar
         files when they are found.

 -v      Print verbose output.

 --keep=mostrecent
         The default option.  If an attribute is associated with a data
         fork, use that.  Otherwise, use information stored in the Apple-
         Double file.  Note that the native fork's data is preferred even
         if the data in the AppleDouble file is newer.

 --keep=dotbar
         Always use information stored in the AppleDouble file, replacing
         any extended attributes associated with the native file.

 --keep=native
         Always use the information associated with the data fork, ignor-
         ing any AppleDouble files.


EXAMPLES
     The following is how to do an dot_clean merge on the mounted volume test,
     always using the dot underbar information.
       dot_clean --keep=dotbar /Volumes/test


DIAGNOSTICS
     The dot_clean utility exits 0 on success, and >0 if an error occurs.
BUGS
     None known.
BSD                              Sept 27, 2012                             BSD

Which filesystems are compatible with both Mac and PC and support extended file attributes

2 Answers2

Appendix