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No vgl_xauth_key after running vglserver_config in ubuntu 13.04

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2014-05-20
2014-05-21
  • jclearwater

    jclearwater - 2014-05-20

    I installed virtualgl 2.3.3 on Ubuntu 13.04. After running vglserver_config and then restarting gdm there is no vgl_xauth_key

    I looked in /etc/gdm/Init/Default and the line
    /opt/Virtual/bin/vglgenkey
    is present but it does not seem to be generating the vgl_xauth_key. Any idea why?

    Note that I initially tried this with lightdm, but there was no vgl_xauth_key generated, so i tried using gdm by:
    sudo /etc/init.d/lightdm stop
    sudo apt-get install gdm
    sudo /etc/init.d/gdm start

    but this did not help.

    Any ideas or advice?

     
  • DRC

    DRC - 2014-05-20

    I have tested VirtualGL on Ubuntu 13, as have others, so I'm not sure what could be wrong. It should work fine with lightdm. Maybe try the latest pre-release in case something that changed since 2.3.3 accidentally fixed this:

    http://www.virtualgl.org/DeveloperInfo/PreReleases

    Otherwise, I'm not sure. All I can do is boot up my installation of Ubuntu 13 and verify that it still works for me, but that gets us no closer to understanding why it doesn't work for you.

    When I run into issues like this (generally on new platforms I haven't tested yet), I'll redirect the output of vglgenkey to a file so I can see why it's failing:

    /opt/VirtualGL/bin/vglgenkey >/tmp/vglgenkey.out 2>&1
    

    That may reveal what isn't working. Perhaps it can't find xauth, for instance.

     

    Last edit: DRC 2014-05-20
  • jclearwater

    jclearwater - 2014-05-20

    Thanks DRC. I get

    xauth: timeout in locking authority file /etc/opt/VirtualGL/vgl_xauth_key

    Could it be a permissions issue? Also, I forgot to mention I'm using PuTTY to ssh into an amazon webserver with ubuntu

     
  • DRC

    DRC - 2014-05-20

    That's a new one. I don't see why it would be a permissions issue, but double-check it just in case:

    drwxr-xr-x 4 root root 4096 Aug 26  2013 /etc/opt
    
    drwxr-x--- 2 root vglusers 4096 May 19 13:57 /etc/opt/VirtualGL
    

    It could also be a SELinux issue. We run into those on RHEL 6 as well. You might try the following:

    semanage fcontext -a -t xdm_rw_etc_t '/etc/opt/VirtualGL(/.*)?'
    restorecon -R -v /etc/opt/VirtualGL
    semanage fcontext -a -t xdm_exec_t /usr/bin/xauth 
    restorecon -R -v /usr/bin/xauth
    

    If that doesn't work, you might even try disabling SELinux. It's an extreme measure, but it would at least tell you if that is the cause of the problem.

     
  • jclearwater

    jclearwater - 2014-05-20

    Thanks again. My permissions are identical to yours. And I don't have SELinux installed.

     
  • DRC

    DRC - 2014-05-20

    No idea, then. For now, you might have to configure VirtualGL to not use vglusers. I don't have time to look at this at the moment.

     
  • jclearwater

    jclearwater - 2014-05-20

    OK, many thanks for your help so far

     
  • jclearwater

    jclearwater - 2014-05-20

    I tried with installing virtualgl2.3.4 but this did not help. I then tried running vglserver_config (n/n/n) so as to not use vglusers, but when I tested with:
    xdpyinfo -display :0
    it returned:
    xdpyinfo: unable to open display ":0".

    Any ideas?

     
  • DRC

    DRC - 2014-05-21

    When you configure it without vglusers, it runs xhost +LOCAL: instead of vglgenkey, but apparently that's failing as well. You probably need to redirect the output of xhost to a temp file as you did above with vglgenkey to see why it's failing.

    This really behaves like an SELinux problem. You're sure it's disabled?

     
  • jclearwater

    jclearwater - 2014-05-21

    I have a folder /selinux/ but there's nothing in it, and when I try:
    sestatus
    I get:
    "The program sestatus is currently not installed"
    Is there anything else I can do to check? Pretty sure ubuntu uses apparmour not selinux, but I'm new to this so it is very possible I'm doing something stupid.

    From in a PuTTY window redirecting xhost +LOCAL: gives:
    xhost: unable to open display ""

    but in a terminal from VNC I get:
    non-network local connections being added to access control list

     
  • DRC

    DRC - 2014-05-21

    No, you're misunderstanding me. Edit /etc/gdm/Init/Default, and the xhost +LOCAL: command should have been added there by vglserver_config. Redirect that command to a temp file:

    xhost +LOCAL: >/tmp/xhost.log 2>&1
    

    so you can see if it is failing and, if so, why.

    SELinux:

    Generally, you can look at /etc/selinux/config to see whether it is enabled or not. If it is, then please try the command sequence I posted above (you may have to install a new package to get the semanage utility. It isn't always installed by default, even if SELinux is enabled.)

    I really can't spend any more unpaid time on this. If you want to pay for an hour of support, I'll be happy to log into your system remotely and fix it (I have a 100% success rate with such things, but it requires tinkering with the system to figure out what's wrong. Very hard for me to communicate my 20 years of experience with diagnosing such problems to someone else. The sequence of steps we've gone through thus far, that has taken a lot of my time and yours, is something I could have gone through myself in about 5 or 10 minutes.) Otherwise, there is really nothing else I can do, but if you do discover a fix on your own, I will be happy to check in the patch or add appropriate documentation.

     
  • jclearwater

    jclearwater - 2014-05-21

    Thanks DRC