cannot mount NFS remote

[djingo]

I am failing to configure a NFS remote for backups.

Situation: I have already read all forum articles on this, and still do not have the solution.

Setup: XO from source running as root in a container with SYS_ADMIN capability on a docker host on a different hypervisor, not any of the XCP-ng hosts. NFS export on an unraid server.

Error messsage:

Command failed with exit code 32: mount -o defaults -t nfs unraid:/mnt/user/backup-xcp-ng /run/xo-server/mounts/ea17b....
mount.nfs: access denied by server while mounting unraid:/mnt/user/backup-xcp-ng

What I have tried so far:
I know that the XO machine must be able to mount from the NFS server, not the XCP-ng host. The NFS share settings are so that the docker host where runs XO is able to mount. If I run showmount -e unraid or the mount directly on the XO docker host it works and I can see the packs for both operations on the network.

However, if I run showmount -e unraid and try the mount command within the XO container, only showmount works and I can see the RPC and MOUNT packets on the network, but no packets for the mount command!

So clearly this is a problem with the container, the mount command does not even reach out to the network (although running as root and with SYS_ADMIN capability).

What could be the problem?

[djingo]

OK I got it. I didn't think that the host was using apparmor, but it actually does.

So it must be started using --cap-add sys_admin --security-opt apparmor:unconfined

Now it works.