Advice for Debugging NFSD


I have a chronic issue with nfsd on my FreeBSD 11.0-RELEASE-p8 server.

The server is offering NFSv3 shares via ZFS exports to five other servers over a private network, and every once and awhile the FreeBSD box needs to be rebooted to get NFS working again.

I say this because I'm unable to restart or kill the nfsd(8) process on the FreeBSD server. Clients can issue showmount(8) commands to the server, but there is no traffic or response.

There is nothing in the messages log, the console or dmesg at the time of the errors, so I'm hoping someone has advice on how to add some logging to NFS on FreeBSD so I can get an idea of what is causing the server to lock up.

During a lock up this morning I ran an freebsd-update fetch install and rebooted into 11.0-RELEASE-p9 so maybe this kernel will be stable???

Appreciate any advice.