Running X on a box with a root mounted on nfs

[Steve King <debian@twobit.demon.co.uk>]

I have built a box to run diskless and everything seems to work
correctly, with one exception.

I cannot connect x clients to DISPLAY=:0 as any user other than
root.

This means that I cannot login using kdm, login window disappears
only to reappear almost immediately.

I cannot run startx/xinit, the X server starts ok, but when startx
tries to connect the client it just prints lines of ".." for a long
time.

I can run X using the command X, but when I try xterm -display :0
it just says that it cannot connect to :0

I *can* run the command X and then xterm -display :0 as root.

Running X without "-nolisten tcp" I *can* connect to <hostname>:0 or
localhost:0

I *can* run X -query eagle, to get a XDCMP login working.

The only thing I can think it is is a problem with Unix Domain
sockets when they are on nfs mounted partition.
I know nothing of unix domain sockets, except that XFree uses them
to connect to :0

Any ideas?

(Sorry for the longish post)

Regards,

--
Steve King

Configuration info:
The system is a 3.0 installation with the latest security patches
applied:
xserver-common: 4.1.0-16woody1
xserver-xfree86: 4.1.0-16woody1
I installed initally using a disk, and a stock kernel. X works
as expected booting on the disk.

I built a kernel, as I have done many times using make-kpkg with
the following changes from the standard kernel (I am not using
initrd):
diff /boot/config-2.4.18-1-k7 /boot/config-2.4.18-1-k7-nfsboot
59,60c59,60
< CONFIG_NOHIGHMEM=y
< # CONFIG_HIGHMEM4G is not set
---
> # CONFIG_NOHIGHMEM is not set
> CONFIG_HIGHMEM4G=y
61a62
> CONFIG_HIGHMEM=y
304c305,308
< # CONFIG_IP_PNP is not set
---
> CONFIG_IP_PNP=y
> CONFIG_IP_PNP_DHCP=y
> # CONFIG_IP_PNP_BOOTP is not set
> # CONFIG_IP_PNP_RARP is not set
777c781
< CONFIG_EEPRO100=m
---
> CONFIG_EEPRO100=y
1504c1508
< CONFIG_NFS_FS=m
---
> CONFIG_NFS_FS=y
1506c1510
< # CONFIG_ROOT_NFS is not set
---
> CONFIG_ROOT_NFS=y
1509,1510c1513,1514
< CONFIG_SUNRPC=m
< CONFIG_LOCKD=m
---
> CONFIG_SUNRPC=y
> CONFIG_LOCKD=y

(as you can see I am using an eepro100. The computer also has enough
memory to need CONFIG_HIMEM)

The graphics card is an old matrox MGA PCI card (until my new GeForce
card arrives, and I can recycle my old GeForce):

/etc/X11/XF86Config-4
### BEGIN DEBCONF SECTION
# XF86Config-4 (XFree86 server configuration file) generated by dexconf,
[...some comments removed]

Section "Module"
        Load    "GLcore"
        Load    "bitmap"
        Load    "dbe"
        Load    "ddc"
        Load    "dri"
        Load    "extmod"
        Load    "freetype"
        Load    "glx"
        Load    "int10"
        Load    "pex5"
        Load    "record"
        Load    "speedo"
        Load    "type1"
        Load    "vbe"
        Load    "xie"
EndSection

Section "InputDevice"
        Identifier      "Generic Keyboard"
        Driver          "keyboard"
        Option          "CoreKeyboard"
        Option          "XkbRules"      "xfree86"
        Option          "XkbModel"      "pc105"
        Option          "XkbLayout"     "gb"
EndSection

Section "InputDevice"
        Identifier      "Configured Mouse"
        Driver          "mouse"
        Option          "CorePointer"
        Option          "Device"                "/dev/psaux"
        Option          "Protocol"              "ImPS/2"
        Option          "ZAxisMapping"          "4 5"
EndSection

Section "InputDevice"
        Identifier      "Generic Mouse"
        Driver          "mouse"
        Option          "SendCoreEvents"        "true"
        Option          "Device"                "/dev/input/mice"
        Option          "Protocol"              "ImPS/2"
        Option          "ZAxisMapping"          "4 5"
EndSection

Section "Device"
        Identifier      "Generic Video Card"
        Driver          "mga"
EndSection

Section "Monitor"
        Identifier      "Generic Monitor"
        HorizSync       30-94
        VertRefresh     50-75
        Option          "DPMS"
EndSection

Section "Screen"
        Identifier      "Default Screen"
        Device          "Generic Video Card"
        Monitor         "Generic Monitor"
        DefaultDepth    24
        SubSection "Display"
                Depth           1
                Modes           "1024x768" "800x600" "640x480"
        EndSubSection
        SubSection "Display"
                Depth           4
                Modes           "1024x768" "800x600" "640x480"
        EndSubSection
        SubSection "Display"
                Depth           8
                Modes           "1024x768" "800x600" "640x480"
        EndSubSection
        SubSection "Display"
                Depth           15
                Modes           "1024x768" "800x600" "640x480"
        EndSubSection
        SubSection "Display"
                Depth           16
                Modes           "1024x768" "800x600" "640x480"
        EndSubSection
        SubSection "Display"
                Depth           24
                Modes           "1024x768" "800x600" "640x480"
        EndSubSection
EndSection

Section "ServerLayout"
        Identifier      "Default Layout"
        Screen          "Default Screen"
        InputDevice     "Generic Keyboard"
        InputDevice     "Configured Mouse"
        InputDevice     "Generic Mouse"
EndSection

### END DEBCONF SECTION