mdm (8) - Linux Manuals

mdm: MDM Display Manager


mdm - MDM Display Manager




mdm is the equivalent of xdm(1x) or wdm(1x), but uses the GNOME libraries to provide a GNOME look-and-feel. It provides the GNOME equivalent of a ``login:'' prompt.

mdm reads /etc/mdm/mdm.conf for its configuration. For each local display, mdm starts an X server and runs mdmlogin(8x) on that display. The main mdm process also listens for XDMCP requests from remote displays. These requests can either be direct, causing mdm to start a mdmlogin(8x) on the remote display, or indirect, causing a mdmchooser(8x) to be opened.

When managing a display, mdm attempts to execute /etc/mdm/Init/display, or /etc/mdm/Init/Default if that does not exist. When a user logs in, mdm first attempts /etc/mdm/PreSession/display (or /etc/mdm/PreSession/Default), and then one of the sessions in /etc/mdm/Sessions. When the session has completed, mdm attempts to run /etc/mdm/PostSession/display, or /etc/mdm/PostSession/Default. Of all these files, only the /etc/mdm/Sessions one is required to exist.

mdm maintains information about the displays it is managing in /var/lib/mdm. This includes xauth information, so this directory is not readable to normal users.

mdm uses PAM to perform authentication using the config file /etc/pam.d/mdm.


Martin Kasper Petersen <mkp [at]>

This manual page written by Steve Haslam <araqnid [at]> for Debian GNU/Linux. Updated by Raphae.l Hertzog <hertzog [at]>. Updated by Ryan Murray <rmurray [at]>.