# Investigating Virtual Session Creation Failure on Linux
<a name="investigating-linux-virtual-session-creation-failure"></a>

A virtual session is [created](managing-sessions-start.md#managing-sessions-start-manual) on Linux with the command: 

```
$ dcv create-session {{session}}
```

This command will return an error only if the creation of the session fails. However, it might happen that the session is initially created successfully, but it terminates before a user can connect. You might notice this because when you check for the existing sessions, for example with the command `dcv list-sessions` or with `dcv describe-session {{session}}`, you might get no listed sessions. 

In most of the cases, this happens because the desktop session is created but then immediately fails, for example in case one of the applications launched by the init script crashed or failed, or in case one of the required tools is missing. 

 Check the following in case the session creation fails: 
+ Check the `/var/log/dcv/sessionlauncher.log` file containing the log related to the dcv component creating the new session processes. 
+ Check the `/var/log/dcv/dcv-session.{{user}}.{{session.log}}` file containing the log related to the dcv init script. 
+ Check the `$HOME/.xsession-errors` file in the home directory corresponding to the session owner. This file contains a log generated by the system X session init script, and usually contains the log generated by the desktop session manager or by other applications called by the script. 
+ Check the system logs to get more information about failing systems and components. As a start, check the output of `dmesg` (e.g in case of a process failure) and `journalctl -xe`. 
+ [Test with a failsafe session](creating-linux-failsafe-virtual-session-creation.md) to verify that the issue does not depend on the session manager in use. 

**In case the failure only occurs to a specific user**, you might also try the following:
+ Check the user configuration, in particular what happens when the user configuration is deleted or renamed.

  Depending on the desktop environment and version, the configuration directory might be `.gnome` or `.kde` or `.config` in the user directory. 
+ Check for specific user configurations affecting the user `PATH` or environment. Quite often, session start failures for specific users are due to frameworks such as `anaconda` overriding some standard native commands that may cause `dbus` connections in sessions initialization to fail. 
+ Check for permission issues. Wrong permissions set on local `~/.dbus` or `~/.Xauthority` (for example they might be owned by `root` instead of the user) might cause a desktop session to terminate immediately.