@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 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.

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.

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.

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.

@tjkreidl I have tried various flavors.

@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?

@tjkreidl what version should I be using or can I force XO to use a particular version?

It doesn't output any more than I shared last time :

bash-5.1# showmount -e 192.168.11.60
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
bash-5.1#

It just occurred to me, I'm running XO in a docker not direct on the host. Do I need some network config to enable NFS?

@tjkreidl

I don't touch things manually, it's done through OMV. This is the exports file. I don't have any multipathing as far as I know. It's not something I've set up.

# This file is auto-generated by openmediavault (https://www.openmediavault.org)
# WARNING: Do not edit this file, your changes will get lost.

# /etc/exports: the access control list for filesystems which may be exported
#               to NFS clients.  See exports(5).
/export/Everyone 192.168.11.0/24(fsid=94a977de-432c-4653-9870-a1cd0a83110d,ro,subtree_check,insecure,crossmnt)
/export/Backups 192.168.11.0/24(fsid=bb941285-c5d8-492d-9b49-43a2dc30557c,rw,all_squash,insecure,async,no_subtree_check,anongid=100,crossmnt)

# NFSv4 - pseudo filesystem root
/export 192.168.11.0/24(ro,fsid=0,root_squash,no_subtree_check,hide)
/export 192.168.11.70(ro,fsid=0,root_squash,no_subtree_check,hide)

@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

@Danp I thought as much and have been playing with the settings without success. I don't know a lot about NFS.

I'm using the following options at present, but have tried with various users and groups, etc.

rw,all_squash,insecure,async,no_subtree_check,anongid=100,crossmnt