Please enable NFSv4.1 in the kernel. I need it to get NFSv4 callback playing nice with a restrictive firewall/VPN configuration. It isn’t disabled by default in Debian Jessie AFAIK.
Hi
What kernel does Jessie ship with? We are currently shipping 3.18 for Pi and 3.14 for Vero. It will also help to know what device you have
We have NFSv4 enabled in the kernel, but your device may be favouring the V3 implementation. Try specify the version as a mount option,
Sam
Jessie ships with 3.16. I’d check a config from /boot, but all my Jessie installs are in containers on an Ubuntu host. I’m using a Pi 2 with NFSv4 because it’s definitely a better option than NFSv3 over a VPN. Looking at the 14.04.1 LTS kernel config, the Ubuntu kernel team definitely enabled 4.1:
CONFIG_NFS_V4_1=y
CONFIG_NFS_V4_2=y
CONFIG_PNFS_FILE_LAYOUT=m
CONFIG_PNFS_BLOCK=m
CONFIG_PNFS_OBJLAYOUT=m
CONFIG_NFS_V4_1_IMPLEMENTATION_ID_DOMAIN="kernel.org"
CONFIG_NFS_V4_1_MIGRATION=y
PNFS is part of the 4.1 spec. Adding the ‘minorversion=1’ option to an NFSv4 mount entry in fstab is then all that is required in Ubuntu. I’m using 4.1 because v4 assigns the back channel port on the server dynamically, which is no good when the service is running behind a restrictive firewall. 4.1 addresses this problem by having the client initiate the back channel instead. If you could just toggle the 4.1 options in future kernel builds, I’d be rather grateful!
Will add it for the next kernel build
Sam
Brill 
Thanks Sam!
This will be part of the July update.
S