Debian Bookworm: Long Delay in Starting Applications via SSH-X

Debian Bookworm: Long Delay Starting Applications via SSH-X

In this article, we will discuss a common issue that arises when using a new Vanilla Debian Bookworm installation on a laptop. Specifically, we will focus on the delay of around 25 seconds that occurs when connecting via SSH-X and attempting to start an application such as gedit.

Understanding the Issue

When connecting to a Debian Bookworm installation via SSH-X, there may be a significant delay before applications start. This delay can be frustrating, especially when trying to be productive. The root cause of this issue is related to how Debian Bookworm handles SSH-X connections and application startup.

Investigating the Problem

To investigate this issue, we need to first understand that SSH-X connections involve two main components: the SSH protocol and the X11 protocol. The SSH protocol handles secure remote login, while the X11 protocol allows for the remote display of graphical applications.

In the case of Debian Bookworm, the default SSH configuration includes X11 forwarding, which enables the remote display of applications. However, the default settings may not be optimized for performance, leading to the observed delay.

Resolving the Issue

To resolve the issue, we can make a few adjustments to the SSH configuration and application settings. Here are the steps to follow:

1. Edit the SSH configuration file (/etc/ssh/sshd\_config) and add the following lines:

   X11Forwarding yes
   X11DisplayOffset 10
   X11UseLocalHost yes

   These settings optimize X11 forwarding and reduce the delay when starting applications.

2. Restart the SSH service to apply the changes:

   sudo systemctl restart ssh

3. Modify the application settings to reduce startup time. For example, when starting gedit, use the following command:

   gedit --no-default-window

   This command starts gedit without displaying the default window, which can reduce startup time.

In this article, we discussed the issue of long delays when starting applications via SSH-X on a new Vanilla Debian Bookworm installation. By adjusting the SSH configuration and application settings, we can significantly reduce the observed delay and improve productivity.

References

• sshd\_config man page

• gedit command line options