Proxmox VE 4.3 and Lightdm - Lightdm won't start

[John Radley]

I have installed Proxmox VE 4.3 on a bare metal server (ASUS H110T) via the repositories, where Debian 8.6 was installed first. Prior to installing Proxmox, the Debian server was working fine, and continues to do so using the Debian v3 kernel.
As soon as I boot with the Proxmox 4.4 kernel, Lightdm (via LXDE) will not start (it tries multiple times and gives up). I think gdm3 has same issue.

In preparation for this install, I did do same with Debian and Proxmox within Virtualbox 5.1.6 (Windows 10 host), where there was no problem with Lightdm and the Proxmox 4.4 kernel.

It's not a big deal - I have disabled Lightdm and use X2go to connect. And my usage is entirely domestic.
But it would be good to hear from Proxmox Gurus as to perhaps why, and any suggestions for troubleshooting the issue.
Thanks
John

 

[fabian]

If it is just lightdm that is failing, you should check the lightdm logs in /var/log/lightdm . I use it on my dev machine without problems

 

[John Radley]

Hi, I did check those logs but they didn't tell me anything useful.
Of course, I should have realised that X was not starting.

It seems that kernel modules i915 and i915_bpo are not working with my ASUS H110T motherboard and your 4.4 kernel.
I blacklisted them and changed to the fbdev driver, by creating /usr/share/X11/xorg.conf.d/20-fbdev.conf, with

Section "Device"
Identifier "Card0"
Driver "fbdev"
EndSection

and X starts sufficiently for my learning Proxmox

You might like to add to your documentation wiki to remind anyone else what to do if X does not start.

 

[oelsi]

I also had this problem on my Skylake Build. Problem was solved by adding "nomodeset" to the kernel command line in GRUB, no X-config changes required.