So I was having a bunch of problems with an NFSv4 (or v3 for that matter) export on my NSLU2. It was giving me a lot of ’stale file handle’ errors, and sometimes downright telling me that files had disappeared.

It would seem that this was all stemming from the use of a VFAT FS on my exported drive. It’s a USB HD that I also sometimes use on WinXP for photo stuff, so I stuck with vfat (back when I chose this NTFS read/write wasn’t *yet* clear). The NFS FAQ has this to say about NFS on FAT shares:

Second, it is a poor idea to export a FAT or VFAT (i.e., MS-DOS or Windows 95/98) filesystem with NFS. FAT is not designed for use on a multi-user machine, and as a result, operations that depend on permissions will not work well. Moreover, some of the underlying filesystem design is reported to work poorly with NFS’s expectations.

After some more googling it would seem that the lack of enough metadata capability in FAT file systems does not make NFS happy.

Incidentally it’s not clear to me whether you can export NTFS read/write over NFS yet since the most recent drivers seem to still be on FUSE.

NTFS-3g has the following to say about that:

Can I export NTFS via NFS?

Yes. There are two solutions depending on the Linux kernel version:

1. Obsolete: Use the FUSE kernel module from the FUSE 2.7.4 software package and please read the FUSE README.NFS file.

2. Preferred: Use the FUSE kernel module included in the Linux 2.6.27 and later kernels.

On their FAQ

So I finally settled with simply using Samba to export the VFAT partition, and that seems to work without issue, and actually has decent throughput (watching some really high bitrate episodes over the network works fine, even from a 266MHz ARM server).