Make X Work on Diskless Linux
The following advice pertains to Fedora Core 6, and possibly other
distributions, when the installation is modified such that the root
filesystem is mounted read-only, and shared among a number of
non-homogeneous systems.
Date: Mon, 25 Jun 2007 15:46:53 -0400
From: Alex Aminoff
Subject: HOWTO.make.X.work.on.diskless.linux
How to make X possibly work on diskless linux
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When a linux machine boots from our diskless root, most applications
just automatically work with whatever hardware happens to be in the
box. A major exception is X windows. Sometimes it will work with the
default configuration, however sometimes auto-generating a
machine-specific configuration will be necessary.
1. Try booting the linux machine diskless without any modifications to
the default. Log in as a normal user and run startx. If the error
messages obviously point to some other problem, like permissions on
/tmp, try fixing those first.
2. The indications of a problem that generating a machine-specific
xorg.conf is likely to fix are: X fails with error messages talking
about drivers, or X starts up but fails to provide signal to the
monitor, so that the monitor gets the "no signal" message. If the
symptoms are something else, this procedure may work, but probably
not.
3. Log in to the machine as root.
4. Create an in-memory file system for the /root directory. This is
necessary because the place where the auto config generation deposits
its output is hard-wired to /root/. On a diskless machine, /root is
normally read-only.
mount -t tmpfs none /root
5. Create the autogenerated xonfig
Xorg -configure
6. Move the resulting file (/root/xorg.conf.new) to where it needs to
go ( /disk/admin/conf//etc/X11/xorg.conf ). This probably has
to happen in 2 steps because you will not have write access to conf from
the diskless machine directly.
7. Reboot the diskless machine and test.