Nick,
I've been using the Proxy FSAL for the past two years and have had much
better results since moving to the V4.dev branch about a year ago,
particularly after Solomon Boulos' improvements to the Proxy FSAL. I
don't claim to be using it exactly as you've described but I believe it
may be worth your while to try the V4.dev branch.
Todd,
Thanks for the hints - I'll give it a shot - either see if packages are available or just compile it myself.
No joy after switching to the V4 Dev branch - behavior seems identical. There's definitely something in the V3 -> V4 proxy that just doesn't work, as mounting the proxied NFS share as NFSv4 from a client works fine, but NFSv3 results in the "Remote I/O Error" behavior.
Here are the things I've tried so far:
* Both versions 3.5 (Current Stable) and V4 dev (latest release).
* Various combinations of Privileged Port enabled/disabled on both the Export and the Proxy FSAL.
* mount_path_pseudo both enabled and disabled to see if the path translation was causing issues for the V3 client.
* Both enabling and disabling Handle Mapping.
I'm open to any other suggestions that folks have for me, and am happy to provide any further debug output.
-Nick