[SOLVED] x11 connection rejected due to wrong authentication

jzoudavy · 04-26-2015, 12:40 AM

hi experts

I got a bit of problem with the below situation:

Code:

root@kvm_host1:/mnt/nfs# virt-manager &
[1] 4663
root@kvm_host1:/mnt/nfs# X11 connection rejected because of wrong authentication.

[1]+  Done                    virt-manager
root@kvm_host1:/mnt/nfs# su test
test@kvm_host1:/mnt/nfs$  virt-manager &
[1] 4679

As you can see, I ssh into my ubuntu host with user test, but during some nfs config I su into root, then try to launch virt-manager GUI via X11. Which obviously fails I guess since root wants to launch X11 session but I established the session as user test.

My question is this: Is there a way to stop this from happening? to allow my root to launch the GUI as well?

Thanks

jpollard · 04-26-2015, 06:06 AM

X doesn't work well when running as root (loss of security mostly, and the ease of "unintended results").

Virt-manager doesn't need root. What does need root is access to the service.

One of the things that MAY be happening (especially if an NFS mount is used for the user logins home directory) is that root is not granted access to the NFS mount. ssh creates/stores the X authentication using xauth, by default xauth will use /home/<user>/.Xauthority. If root isn't granted NFS access, then it cannot read the users .Xauthority file. The blocking (if the NFS server is Linux) is usually "root_squash", which maps uid 0 to the anonymous uid (nfsnobody).