I'll attach the original test file I created and attempted to move to
the wheezy box, in groups of 4-5 lines:
--
Graeme
root@vjessie:/mnt# uname -a
Linux vjessie 3.16-2-amd64 #1 SMP Debian 3.16.3-2 (2014-09-20) x86_64 GNU/Linux
root@vjessie:/mnt# dpkg -l | grep xdm
ii libxdmcp6:amd64 1:1.1.1-1 amd64 X11 Display
Manager Control Protocol library
ii xdm 1:1.1.11-1 amd64 X display manager
root@vjessie:/mnt# dpkg -l | grep gdm
ii gdm3 3.14.0-1 amd64 GNOME Display
Manager
ii gir1.2-gdm3 3.14.0-1 amd64 GObject
introspection data for the GNOME Display Ma
ii libgdm1 3.14.0-1 amd64 GNOME Display
Manager (shared library)
This is an issue with jessie but not wheezy.
XDMCP connections to Jessie+gdm3 fail after a few seconds, while Jessie+xdm
work fine.
Environment:
real machine (DNS name= "real.home") runs Fedora20 , and qemu+kvm.
Virtual machines exist (e.g vdebain.home [wheezy] , vjessie.home )
Normal usage would be on "real.home" on another console (ALT-F3 etc) start:
X :2 -query 10.116.1.53 (address of vjessie)
If vjessie is running xdm , this works fine. If vjessie runs gdm3 it works for
about a minute, then just keeps dropping back to black X sreen (with X cursor)
SETUP:
On jessie:
install xdm, choose xdm as the default display manger.
Edit /etc/X11/xdm/xdm.config: (comment out the disable requestPort]
! Comment out this line if you want to manage X terminals with xdm
! GPV (previously was NOT commented) DisplayManager.requestPort: 0
*restart"
root@vjessie:/etc/X11/xdm# lsof -i:177
COMMAND PID USER FD TYPE DEVICE SIZE/OFF NODE NAME
xdm 906 root 4u IPv6 1923 0t0 UDP *:xdmcp
From "real.home" :
ALT-F3
X :2 -query vjessie.home
On ALT-F1, a xmd logon screen appears.
After giving userid+password, a jessie screen (need to authenticate to manage
color managed console)
pops up and requires a passsword [ this is new and does not happen in wheezy ]
after authenticating
a normal desktop appears and works fine.
On jessie, do:
dpkg-reconfigure xdm
And choose gmd3
start-stop-daemon: pid value must be a number greater than 0
Try 'start-stop-daemon --help' for more information.
*restart*
Get gdm3 logon, after giving password, you get prompted with jessie screen (need
to authenticate to manage color managed console) , after authenticating, you
get a normal
jessie (gdm) desktop. Start an xterm and wait a minute or so. You get dropped
back to a plain black
X terminal (cursor is big X).
...from this point on, after switching to another console (one real.home),
about once a minute , it switches back to
ALT-F1 and the blank X terminal. This pattern repeats.
In vjessie:/var/log/messages: there are messages about "out of video memory"
(which may well relate to what is happening)
Oct 25 18:33:53 vjessie gdm-Xorg-:0[3495]: Out of video memory: Could not
allocate 4378332 bytes
Oct 25 18:33:53 vjessie gdm-Xorg-:0[3495]: - 0th attempt
Oct 25 18:33:53 vjessie gdm-Xorg-:0[3495]: - OOM at 1109 986 24 (= 3280422
bytes)
Oct 25 18:33:53 vjessie gdm-Xorg-:0[3495]: Cache contents: null null null null
null null null null null null null null null null null null null null null null
null null null null null null null null null null null null null null null null
null null null null null null null null null null null null 339 333 330 350
338 343 336 355 1015 354 739 976 1016 977 1011 1003 total: 16
Oct 25 18:33:53 vjessie gdm-Xorg-:0[3495]: Out of video memory: Could not
allocate 4378332 bytes
Oct 25 18:33:57 vjessie gdm-Xorg-:0[3495]: qxl_surface_create: Bad bpp: 1 (1)
Oct 25 18:34:22 vjessie gdm-Xorg-:0[3495]: qxl_surface_create: Bad bpp: 1 (1)
Oct 25 18:34:38 vjessie gdm-Xorg-:0[3495]: qxl_surface_create: Bad bpp: 1 (1)
But **NOTE** these messages are on vjessie.home. This is an XDMCP type login,
so the Xterminal is on "real.home" where there are NO
messages. The virtual machine (vjessie) had a QXL display with 64Mb ... note
qxl_surface in the above message.
I wonder if gdm is attepting to use the wrong display?
Using gmd3 via SPICE, seems to work fine (wheezy was very poor in this mode)
but it is something like 100 times faster using XDMCP.
