On 2014-12-22 13:43, Chris Murphy wrote: > On Mon, Dec 22, 2014 at 11:09 AM, Austin S Hemmelgarn > wrote: > >> Personally, I'd love to see unlimited length xattr's like NTFS and HFS+ do, >> as that would greatly improve interoperability (both Windows and OS X use >> xattrs, although they call them 'alternative data streams' and 'forks' >> respectively), and provide a higher likelihood that xattrs would start >> getting used more. > > This is two years old, but it looks like NFS will not support xattr. > http://comments.gmane.org/gmane.linux.nfs/53259 > > It looks like SMB does support xattr (and sometimes requires it) but I > have no idea to what degree, including the host/client preservation on > different filesystems. [1] It would still be helpful for cp and rsync > to be able to preserve xattr, however Apple has moved to a new on-disk > format that makes the future of reading OS X volumes on Linux an open > question. [2] > > > > > [1]e.g. Btrfs > Samba- server > SMB over TCP > "Apple SMB2" > HFS+. > And then the OS X client pushing a file to the server is a separate > test. Next test would be OS X as server and Linux as client to do HFS+ >> "Apple SMB2" > SMB over TCP > Samba-client > Btrfs, and then Linux > client pushing a file to OS X is a separate test. So it's four tests > for any combination of filesystems. > > [2] Apple has a logical volume manager called CoreStorage. Until > recently it's mainly used to implement full disk (volume) encryption, > but encryption is actually optional. It's also used to combine SSD+HDD > partitions into a single logical volume using the SSD as a cache. > Starting with 10.10 "Yosemite" it's used by default for the main > HFSJ/X volume for system/apps/user data, and even legacy OS X only > installations are converted to a CoreStorage logical volume upon > upgrading. There's no pre-baked support on linux for this right now, > and I'm not really sure if/when we'd ever see this in a distribution > by default. > http://www.cl.cam.ac.uk/~osc22/docs/cl_fv2_presentation_2012.pdf > https://github.com/libyal/libfvde/ > > I'm more thinking along the lines of not having to jump through hoops to get _ALL_ the data in a tar file from OS X to extract on a Linux box. Also, Windows has been using it's 'alternative data streams' functionality from NTFS more in recent years (the new 'file history' functionality in Win8/8.1 uses ADS for storing old copies of files), and these are essentially just forks with a extra compatibility interface. There are other potentially interesting uses though, for example, storing multiple localized versions of a text file as a single user-visible 'file'.