XO Remote mount.nfs: access denied by server while mounting

HeMaN

@Danp said in XO Remote mount.nfs: access denied by server while mounting:

@daninmanchester said in XO Remote mount.nfs: access denied by server while mounting:

"stderr": "mount.nfs: access denied by server while mounting 192.168.11.60:/Backups",

Would appear to be a rights issue to me.

@tjkreidl verified they can be seen :

Export list for 192.168.11.60:
/export/Backups 192.168.11.0/24
/export/Everyone 192.168.11.0/24
/export 192.168.11.0/24

do you need to add "/export" (/export/Backups ) to be able to find the right path?

tjkreidl

@HeMaN Yes, if I recall correctly, in the /etc/exports file. the full path should be specified and then "exportfs -a" should be issued to refresh the export list.
I just noticed your error message doesn't include the /export directory in front:
mount.nfs: access denied by server while mounting 192.168.11.60:/Backups

daninmanchester

@Danp no, I hadn't seen that. but I think I have now done this without any change to my issue. One thing that wasn't 100% clear is where sudoers should be on docker.

/etc/sudoers?

daninmanchester

@tjkreidl I have tried various flavors.

daninmanchester

Well .... I'm totally baffled.
I've tried reapplying permissions.
forcing the server UID/GID
forcing the client UID/GID.
NOACLs
Squashing.

One thing I can say, is that it is working on my host so it must be something about my XO setup trying to talk to it. which may well still be permissions.

daninmanchester

okay, so I further narrowed it down. on the host machine I can mount. it is only within the docker container it is the issue. either at the command line or at XO. This leads me to believe this is a docker related problem not XO.

Sorry to have taken up your time, but thanks very much for your help!
At least i have a clear direction to google now.

mjtbrady

@daninmanchester

What is the IP address of the host that is running XO?

The docker container will need the SYS_ADMIN capability to do NFS mounts.

tjkreidl

@daninmanchester I would think Docker is involved, as well. I was going to suggest to create a "standard" test VM ans see if you can connect storage to it. If so, that would put the blame on something specific to the VM that has that Docker container.

tjkreidl

@mjtbrady That seems right, because the Docker instanceis independent and internal to the VM that otherwise is part of the XCP-ng networking structure and wouldn't have the necessary access permissions on it's own.

Danp

Could this be due to a missing package (nfs-common)?

daninmanchester

I setup another VM as someone suggested and the NFS share mounted and worked. So there is something I am not understanding about docker permissions / requirements.

In the end, following a permissions reset and forcing the NFS share to squash and use my user/group ID I think I have progress. I can see it is writing to the NFS share.

Then I got : EEXIST: file already exists, open '/run/xo-server/mounts/6299d107-2aa2-41bf-bfd7-2f487ff5422f/xo-vm-backups/801e2b10-5c7d-b7af-ad5e-fbcc83e47d5b/.20220930T221548Z.xva'

A quick google led me to this being related to nfs 3. I switched to NFS 4 then I got path not found.

Not sure why, but I tried removing "export" from the path and it worked.

It does appear now to be running a backup job .... fingers crossed.

What a mine field!

Thanks for all the pointers.

tjkreidl

@daninmanchester Yes, a mine field is about right. Super good ou have made so much progress!

olivierlambert

Now you understand why we sell/distribute XO in a virtual appliance we can test

daninmanchester

@olivierlambert I think the intricacies of NFS, my seemingly borked NFS permissions were likely the real issue. I rarely have real problems with XO. I tried proxmox but didn't get on with it so switched back.

I'm just a home / homelab user, but always impressed with the community around XCP-NG too and have learnt a huge amount from Lawrence Systems.

Anyway this morning I have a successful backup completed :

Thanks again.

olivierlambert

Great news! Enjoy

parallax

@daninmanchester Thanks so much - this is the exact same problem I had, which was further complicated by running XO in Docker running on the OMV host exporting the NFS shares.

So basically you just built a small XO VM instead of running it in Docker? I had originally been thinking of making a small VM to run XO in a container there - just because Docker containers are super easy to keep updated and I could run some other orchestration-y stuff there too, like Rancher - but if you're saying that's a non-starter I'll just bite the bullet and build a tiny VM dedicated to XO and be very grateful to you for having saved me a lot of frustration.