unable to use nfs client to mount nfs in Ubuntu 22.04

[Albert Vilella]

https://askubuntu.com/questions/1405231/unable-to-mount-nfs-on-ubuntu-22-04

I've installed Ubuntu 22.04 on a machine and I am trying to mount an NFS share which has no problems mounting on an array of other Linux Ubuntu machines (21.04, 20.04, 18.04, etc.).

The command we use is:

```
sudo apt install nfs-common # Only required once for installation
sudo mount -t nfs 10.234.123.11:/bfx_share1 /bfx_share1
```

If I do a:
```
sudo showmount -e 10.234.123.11
```
It shows the list of possible mounts, so everything is kosher in that respect.

It's just stuck there, not doing anything. Any ideas? Anything I can do or add to debug the situation? Any other clients not `nfs-common`?

I've installed `nfstrace` and while trying to mount the nfs folder, I kicked it off in another terminal, to obtain the prompt below:

```
## On one terminal
(base) user@LS6-MS-7D04:~$ ping 10.234.123.11
PING 10.234.123.11 (10.234.123.11) 56(84) bytes of data.
64 bytes from 10.234.123.11: icmp_seq=1 ttl=64 time=0.202 ms
64 bytes from 10.234.123.11: icmp_seq=2 ttl=64 time=0.122 ms
64 bytes from 10.234.123.11: icmp_seq=3 ttl=64 time=0.172 ms
^C
--- 10.234.123.11 ping statistics ---
3 packets transmitted, 3 received, 0% packet loss, time 2027ms
rtt min/avg/max/mdev = 0.122/0.165/0.202/0.033 ms
(base) user@LS6-MS-7D04:~$ sudo mount 10.234.123.11:/bfx_share1 /bfx_share1

## In the other terminal with nfstrace running

root@LS6-MS-7D04:/home/user# nfstrace -Z user
Log file: nfstrace.log
Read from interface: enp111s0
  BPF filter : port 2049 or port 445
  snapshot len: 65535 bytes
  read timeout: 100 ms
  buffer size : 20971520 bytes
  promiscuous mode: on
  capture traffic : inout
Processing packets. Press CTRL-C to quit and view results.
Detect session 10.234.123.8:902 --> 10.234.123.11:2049 [TCP]
Detect session 10.234.123.8:772 --> 10.234.123.11:2049 [TCP]
10.234.123.8:772 --> 10.234.123.11:2049 [TCP]NULL
        CALL []
        REPLY []
Detect session 10.234.123.8:947 --> 10.234.123.11:2049 [TCP]
10.234.123.8:947 --> 10.234.123.11:2049 [TCP]NULL
        CALL []
        REPLY []

```

Looking at the release notes of Ubuntu 22.04 (Jammy Jellyfish Release Notes):
https://discourse.ubuntu.com/t/jammy-jellyfish-release-notes/24668?_ga=2.137381111.630065420.1651222708-2033241278.1650531954

There is a section:
```
UDP disabled for NFS mounts
Since Ubuntu 20.10 (“Groovy Gorilla”), the kernel option CONFIG_NFS_DISABLE_UDP_SUPPORT=y is set and this disables using UDP as the transport for NFS mounts, regardless of NFS version.

In practice, if you try to use udp, you will get this error:

$ sudo mount f1:/storage /mnt -o udp
mount.nfs: an incorrect mount option was specified

###

NFS server
The NFS server and client packages have finally been updated to the latest upstream version.

All NFS services now read their configuration from /etc/nfs.conf and /etc/nfs.conf.d/*.conf, which is an INI-style configuration file, where each section is about one daemon or aspect of the NFS service. The old /etc/defaults/nfs-* configuration files are still left around, but are unused.

During upgrade, a conversion script is run if the package detects that the /etc/default/nfs-* files have been changed. This script is /usr/share/nfs-common/nfsconvert.py and it will read the options from /etc/defaults/nfs-* and generate /etc/nfs.conf.d/local.conf, which overrides the defaults in /etc/nfs.conf.

If the conversion script fails for some reason, the package installation or upgrade will fail, and the issue will have to be resolved. Please file a bug against nfs-utils in Launchpad 2 if you encounter such a scenario.

A new tool called nfsconf(8) can be used to query the configuration settings of /etc/nfs.conf and /etc/nfs.conf.d/*.conf.

##

the CTDB package was adjusted to work with the new NFS server version shipped in this Ubuntu 22.04

```

[Andreas Hasenack (ahasenack)]

> It's just stuck there, not doing anything. Any ideas? Anything I can do or add to debug the
> situation? Any other clients not `nfs-common`?

Have you checked firewall rules? Please also check (and attach) /var/log/syslog, the actual output of `showmount -e <server>`, and dmesg recent output.

[John Steele Scott (toojays)]

I was also unable to use NFS mounts since upgrading my client to 22.04. My server is a QNAP running version 5.0.0.1986.

Enabling NFSv4 on the server did not solve the issue.

Adding vers=3 as a mount option on the client lets NFS mounts work again for me.

[Andreas Hasenack (ahasenack)]

> I was also unable to use NFS mounts since upgrading my client to 22.04.

I believe even previous versions of Ubuntu defaulted to NFSv4 on the client when mounting a remote filesystem. From which ubuntu release did you upgrade? You didn't have to force vers=3 in that older release?

[Jeremy Hunt (jtheh)]

I was having the same issue and noticed this in the tcpdump output

16:15:46.208001 IP host2.812 > host1.nfs: Flags [P.], seq 4841:5005, ack 4301, win 501, options [nop,nop,TS val 4079397255 ecr 3402330946], length 164: NFS request xid 379063175 160 getattr fh 0,2/53
16:15:46.208248 IP host1.nfs > host2.812: Flags [P.], seq 4301:4401, ack 5005, win 189, options [nop,nop,TS val 3402346046 ecr 4079397255], length 100: NFS reply xid 379063175 reply ok 96 getattr ERROR: Request couldn't be completed in time

mounting with -o vers=4.0 worked as a temp workaround, but just updated my Qnap to 5.00.2055 and now I can mount with vers=4.2 with no issues.

[Andreas Hasenack (ahasenack)]

You can also use, on the client, `rpcinfo -s <server>` to see what is supported on the server and which version and if it's via tcp, udp, or both.

[Launchpad Janitor (janitor)]

[Expired for nfs-utils (Ubuntu) because there has been no activity for 60 days.]