This document will help you to troubleshoot Xorg problems.

When you encounter a problem with Xorg, please check the following questions:

1. Since when does the problem happen?
2. did it ever work?
3. does it happen only on one machine?
4. does it happen only with one user?
5. were there config changes?

Troubleshooting Documents:

1009360.1: Sun Ultra 20 Workstation: Cannot start X Windows after configuring an NVidia Quadro FX 1400 graphics card

1011133.1: setup and troubleshooting of Xorg..

1018945.1: Redirecting display to a local monitor on the Sun Fire™ X2100, X4100 & X4200 servers

For troubleshooting please check the following files:
/var/log/Xorg.0.log - Xorg writes a logfile to /var/log/Xorg.0.log. The exact name of the log can vary from Xorg.0.log to Xorg.8.log and so forth or like Xorg.0.log.old.

/etc/X11/xorg.conf - this is the Xorg configuration file

FAQ:

http://wiki.x.org/wiki/FAQ
http://wiki.x.org/wiki/FAQErrorMessages
http://wiki.x.org/wiki/FAQWarningMessages
http://wiki.x.org/wiki/FAQVideoModes

Question : unable to launch more than 215 Xclient sessions in X86

Answer: The Solaris X servers have limits on the number of client connections and other open file descriptors.

For Xsun, the -clients option lets you choose between 128 & 1024. For Xorg, it's currently always hardcoded to 256.

The difference they're seeing is thus because Xsun is the default X server on SPARC, while Xorg is the default on x86.

When you get the "Maximum number of clients reached" message, running pfiles on the X server process should show it has hit it's limit of 256/1024 open file descriptors and can't open any more files.

You should be able to get to near the same limit as Xsun on SPARC then, but you'll have support for a lot fewer graphics cards (especially newer models), and will still have to convert to Xorg when upgrading toOpen Solaris or future (post-Solaris-10) versions of Solaris, as Xsun is EOL and removed from Open Solaris (on SPARC & x86) and Solaris Nevada/Express (on x86 now, on SPARC soon).