By default, users can run only one server at once.
Named servers functionality in JupyterHub can be activated to let the user run several servers.
To allow up to 2 simultaneous named servers (in addition to the default one), create the file
in the directory
/opt/tljh/config/jupyterhub_config.d with the following content:
c.JupyterHub.allow_named_servers = True c.JupyterHub.named_server_limit_per_user = 2
Then, reload tljh:
sudo tljh-config reload
Have a look at the named servers documentation for more details.