When I add macOS "labels/tags" on a file or directory from a Unraid share via samba protocol it adds EA data:
root@Tower:/mnt/user/testshare# getfattr test_folder/
# file: test_folder/
user.DOSATTRIB
user.DosStream.com.apple.metadata:_kMDItemUserTags:$DATA
user.org.netatalk.Metadata
Additionally, 'getfattr' will show the values, along with the keys above, with the -d argument.
I did another test involving a cache pool setup:
Created another share named 'cache-first' with Cache mode set to 'only.'
Browsed to the 'cache-first' share from a mac, created a new folder, and then applied macOS "tags" to it.
Verified those EAs were present using 'getfattr folder-name'.
Change 'cache-first' Share's Cache mode to 'yes'.
Run the mover
Verified 'cache-first' share exists on the array now, and the EAs are still present. My mac again shows the correct "tags" I added previously.
I can also copy/move files or folders between my mac and Unraid, in either direction, and the "tags" persist.
macOS version 10.14.6
Unraid version 6.8.3
Two BTRFS formatted SSDs in my Cache Pool
Array disks all XFS-luks
If you're working from a terminal, using 'cp,' 'rsync,' or 'scp' for example, ensure you provide any arguments you may need to preserve xattr.