Crazy screen flicker late in system boot cycle (never stops), OMV5

  • Hi all,


    I suspect this is more of a Debian kernel issue rather than an OMV issue but it's happening on my Dell M4800 Precision laptop that I have been using as my OMV / compute workhorse.


    In the last week, I've rebooted the system twice. Both times at a certain point late in the boot cycle the screen starts flickering like mad. (Mainly horizontal lines, all different colors.)


    I ran the hardware BIOS full system check, nothing shows as having problems.


    Googling turned up a few people on Ubuntu forums having similar issues, which they traced to "something" in the kernel. (Nobody had a definitive fix.)


    I booted into the SystemRescue CD and ran startx ... that started up fine, no issues, so whatever is causing this is coming later in the boot cycle.


    I'm not a kernel / drivers / hardware guy, never saw this happen until the last 7 days. Given that the BIOS h/w diagnostics say everything is fine, I don't think the screen is dying.


    (I had made no changes to the underlying system setup since I installed OMV, it's just been running some VirtualBox images and Samba shares.)


    I'm at a wall of what to do.


    Help?

  • Annnddd... another reboot...


    As expected, screen flicker showed up again... but after about 60 seconds it stopped, and the usual black base login screen appeared.


    Kernel: Linux omv5.local 5.9.0-0.bpo.2-amd64 #1 SMP Debian 5.9.6-1~bpo10+1 (2020-11-19) x86_64 GNU/Linux


    This is bizarre. ;(

  • Well, the system is designed to be headless, so I'm not sure why this would be a concern at all? Just disconnect the display and manage it via SSH.


    If you're running it with a Desktop, which is explicitly advised against.. you're on your own.

    Air Conditioners are a lot like PC's... They work great until you open Windows.


  • Well, the system is designed to be headless, so I'm not sure why this would be a concern at all? Just disconnect the display and manage it via SSH.


    If you're running it with a Desktop, which is explicitly advised against.. you're on your own.


    Missed the point. The whole screen had been flickering insanely. As in, so bad that it causes headaches to even look at it.


    This isn't about using it as an X display, it's about being usable at all.


    It's so bad it's not even possible to log in at the console ... there's no "login:" text.

  • Seriously? Here's a thought: If you don't know, just say "I don't know, sorry".



    Otherwise, please read the thread again.


    This describes the issue, except it is oriented toward Windows users:


    * accatech.com/fix-flickering-dell-laptop-screen/


    This describes the issue that Ubuntu users have faced; except, this is a stock OMV install. (No X display, all I'm trying to do is basic boot to console.)


    * askubuntu.com/questions/1062031/screen-flickering-in-ubuntu-18-04-1-lts


    The AskUbuntu forum posts suggest that the issue is a driver inside the kernel.


    I did not install X. The reference to "startx" in the OP was re: the tools available when using SystemRestore CD.


    The only changes I know of for this kernel are from when I installed kernel headers in order to install VirtualBox and manage with phpVirtualBox.

  • I'm saying why make a mountain out if a molehill? My server for some reason will only work at 800x600. Makes installing a bit if a pain, but once I'm installed.. I just disconnect the cable and never worry about it again.


    So I understand the issue perfectly

    Air Conditioners are a lot like PC's... They work great until you open Windows.


  • Otherwise, please read the thread again.


    This describes the issue, except it is oriented toward Windows users:


    OMV was not designed to be used in console mode with a monitor attached. A lot of effort went into the GUI that is accessible with a web browser, over a LAN connection because it's a Network Attached Server. (NAS) I have servers that haven't had a monitor attached in years.

    But if you're worried about screen flicker in console mode, please note the following:
    - The video connection is handled by Debian. (Not OMV)
    - The console's resolution is primitively low (VGA) so that nearly any video card / monitor combination can handle it. +99%
    - You might have a hardware issue, maybe a hardware fault, or Debian doesn't know to work with your video adapter.

    None of the above matters "if" **Edit** you set BIOS so you can close the laptop lid and use a web browser to connect by IP address or SSH into the server, per the design.

    If you're not sure what the above means, take a look at the New User Guide to get started. Since your installation is complete, you can begin at Initial Configuration.

  • He didn't specifically say it was a laptop, just pointed to a thread that was having a similar problem.... but anyway, the point still stands.. who cares?


    If it bothers you that badly, close the laptop lid (as mentioned, disable sleep in the bios).. or, close it just enough so it doesn't go to sleep... or, get really wild, and just turn the laptop around so you can't see it. Problem solved.


    Again, you're making a mountain out of a molehill. You can try some kernel options (nomodeset, etc..) but those can sometimes can fix one problem and cause 2-3 more.

    Air Conditioners are a lot like PC's... They work great until you open Windows.


  • There is a grub config setting that can be changed to prevent any screen flicker, there is also a setting to prevent the laptop going into suspend mode when the lid is closed.

    Raid is not a backup! Would you go skydiving without a parachute?

  • There is a grub config setting that can be changed to prevent any screen flicker, there is also a setting to prevent the laptop going into suspend mode when the lid is closed.

    Thank you geaves. grub "nomodeset" option made the flicker go away. It appears this is a display driver issue, but everyone who's posted in myriad forums always noted that they saw the flicker problem when running X rather than at the console.


    It would have been nice if the others had tried to actually help.

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