On 25/11/2020 22:51, Richard Kimberly Heck wrote:

I can mount fine. The problem is that various programs (LyX, LibreOffice) freeze when attempting to open files on those filesystems. In LyX, I was able to trace the problem to a call to lockd, which never returns. So it seems there is some problem with file locking, which it was suggested involved some firewall problem. Which it does, since disabling the firewall on the server solves the problem. (There's no firewall on the client.)

OK, sorry, I was only thinking about the initial post.

I tested and found some problems opening a file with LibreOffice in "edit" mode when using NFS-v3.
It would only open "read only".  Get a message from lockd that user is "unknown".  Too early in my
AM to track this down.  It maybe related to idmapd.  Will see if I can find the cause later today.

Thanks for the help. It's much appreciated.

Just to clarify: Stopping the firewall solves my problem.

I enabled firewall debugging and tried to open a LyX file on the nfs share. I started seeing lots of these:

Nov 25 16:18:54 master kernel: FINAL_REJECT: IN=enp2s0 OUT= MAC=00:30:18:a6:7c:04:18:31:bf:4e:e7:a3:08:00 SRC=192.168.1.51 DST=192.168.1.2 LEN=60 TOS=0x00 PREC=0x00 TTL=64 ID=21519 DF PROTO=TCP SPT=872 DPT=36389 WINDOW=64240 RES=0x00 SYN URGP=0
Nov 25 16:18:57 master kernel: FINAL_REJECT: IN=enp2s0 OUT= MAC=00:30:18:a6:7c:04:18:31:bf:4e:e7:a3:08:00 SRC=192.168.1.51 DST=192.168.1.2 LEN=60 TOS=0x00 PREC=0x00 TTL=64 ID=49938 DF PROTO=TCP SPT=872 DPT=36389 WINDOW=64240 RES=0x00 SYN URGP=0

192.168.1.51 is the client; .2 is the server.

I then rebooted and tried a LibreOffice file:

Nov 25 16:24:15 master kernel: FINAL_REJECT: IN=enp2s0 OUT= MAC=00:30:18:a6:7c:04:18:31:bf:4e:e7:a3:08:00 SRC=192.168.1.51 DST=192.168.1.2 LEN=60 TOS=0x00 PREC=0x00 TTL=64 ID=33548 DF PROTO=TCP SPT=853 DPT=38641 WINDOW=64240 RES=0x00 SYN URGP=0
Nov 25 16:24:18 master kernel: FINAL_REJECT: IN=enp2s0 OUT= MAC=00:30:18:a6:7c:04:18:31:bf:4e:e7:a3:08:00 SRC=192.168.1.51 DST=192.168.1.2 LEN=60 TOS=0x00 PREC=0x00 TTL=64 ID=58996 DF PROTO=TCP SPT=853 DPT=38641 WINDOW=64240 RES=0x00 SYN URGP=0

I don't know if it matters, but I also see

Nov 25 16:24:37 master kernel: FINAL_REJECT: IN=enp2s0 OUT= MAC=00:30:18:a6:7c:04:18:31:bf:4e:e7:a3:08:00 SRC=192.168.1.51 DST=192.168.1.2 LEN=84 TOS=0x00 PREC=0x00 TTL=64 ID=19835 DF PROTO=UDP SPT=810 DPT=57620 LEN=64

pretty much as soon as I boot.

I will see if I can reconfigure the server to use NFS-v4.

Riki