On Thu, Aug 06, 2020 at 02:16:11PM -0700, jo...@armadilloaerospace.com wrote: > I tried to mount a 12TB USB drive, and was getting an "Inappropriate > file type or format" error. > > It turned out to be due to exFAT formatting, but it took me some > investigating to figure that out. Would it be reasonable to have the > kernel print a more informative warning like "exFAT filesystem not > supported" when you try to mount it with mount_msdos, or are additional > kernel prints considered bad form?
Yes, EFTYPE error is pretty much the best you can do. mount_msdos is only for FAT12/16/32, in the same way you can't mount FFS with it or NTFS. More informative errors here would require writing a lot more parsing code in the kernel, which is already a sensitive area. > With Microsoft's release of the spec last year, is the path open for > kernel support now, when someone gets around to it? I don't know the details, but I believe one issue with exFAT has been Microsoft and software patents, not just available documentation. Linux may eventually get a kernel implementation but I'm not sure that helps us. https://www.zdnet.com/article/microsoft-readies-exfat-patents-for-linux-and-open-source/ Maybe that's not important, and it's just a lack of both interest and capable developers hacking on new filesystems. > I have seen some comments about the reliability of exfat-fuse, will I > be sad if I try to use it for something important? I mean, can mount the volume read-only if you don't intend to write. If interoperability isn't a concern, choosing a different filesystem (e.g. FFS2) might be alternative option. Hope that helps, -Bryan.
