Black screen & LDAP login problems

[alienpriv]

Hello,

We are experiencing issues with NoMachine on our Ubuntu 22.04 workstations (GNOME, NVIDIA RTX 4080) with local and LDAP users. The problems are as follows:

1. Local Users:

• NoMachine connection works fine

2. LDAP Users Issue:

NoMachine is provided with LDAP login credentials and correctly connects to the Ubuntu login screen.
After logging in to Ubuntu, NoMachine client shows black screen; however the physical workstation logs in correctly to Ubuntu.

After terminating the NoMachine connection each new attempt will show “Cannot detect any display” message, both for LDAP and local users.

After that when connecting as local user, NoMachine asks if we want to create new display, but still doesn’t manage to create one. It never asks that when connecting as LDAP user. Reboot is neccessary

NoMachine client/server version: 8.16.1

Attaching logs of connections as local and LDAP user

LDAP and local users have separate home folders location. Home directories for LDAP users are mounted dynamically using autofs from an NFS share.

We would appreciate any insights or troubleshooting steps to resolve these issues. Please let us know what additional information would be helpful.

Thanks in advance for your support!
Lukas

Attachments:

1. pixelmaker-016-2025-02-25-10.50.11-local_user.zip
2. pixelmaker-016-2025-02-25-10.52.31-LDAP_user.zip

[Britgirl]

This is an LDAP issue related to some mis-configuration which we were unable to pinpoint. We were not able to reproduce this issue even with the user’s same configuration.

In a working and correctly configured environment, LDAP and local users have separate home folders location. Home directories for LDAP users are mounted dynamically using autofs from an NFS share. Based on the logs provided, there is a problem with create file ‘options’ and setting ownership for it in the case of LDAP users (so those who have mounted homedir during login to system).

After considerable investigation, the workaround proposed in this case is to set the following key in the node configuration file to point to a local directory instead of the remotely mounted one:  UsersDirectoryPath /some/local/path.

[Author]

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