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[Bug 582145] Re: Virtual guests' console is unusably slow due to framebuffer usage


Maarten Bezemer, thank you for your comment. So your hardware and problem may be tracked, could you please file a new report with Ubuntu by executing the following in a terminal while booted into a Ubuntu repository kernel (not a mainline one) via:
ubuntu-bug linux

For more on this, please read the official Ubuntu documentation:
Ubuntu Bug Control and Ubuntu Bug Squad: https://wiki.ubuntu.com/Bugs/BestPractices#X.2BAC8-Reporting.Focus_on_One_Issue
Ubuntu Kernel Team: https://wiki.ubuntu.com/KernelTeam/KernelTeamBugPolicies#Filing_Kernel_Bug_reports
Ubuntu Community: https://help.ubuntu.com/community/ReportingBugs#Bug_reporting_etiquette

When opening up the new report, please feel free to subscribe me to it.

Thank you for your understanding.

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  Virtual guests' console is unusably slow due to framebuffer usage

Status in “linux” package in Ubuntu:

Bug description:
  This was also discussed in https://lists.ubuntu.com/archives/ubuntu-

  The problem is that the console of a Ubuntu 10.04 (server) virtual
  machine/guest becomes incredibly slow and really unusable as soon as
  it starts scrolling. This is apparently due to the kernel switching on
  the console framebuffer which does not play well with the VNC-based
  console viewers of virt-manager. I have created a screencast to
  demonstrate, please find it here: https://daff.pseudoterminal.org/misc

  I have experienced this using KVM and virt-manager/virt-viewer on
  Ubuntu 10.04 and Ubuntu 9.10 hosts (using the server edition, FWIW).
  Apparently it also happens with VirtualBox but I have not tested this
  myself. The only solution for the time being seems to be to blacklist
  the vga16fb module as suggested by Paul Nuffer:

      $ echo "blacklist vga16fb" | sudo tee -a /etc/modprobe.d/blacklist

  Merely adding "nomodeset" to the kernel boot options is not

  I don't even know exactly to which package this bug belongs let alone
  what to do about it except force the kernel not to use a console
  framebuffer. I know Plymouth needs the framebuffer to display splash
  screens and whatnot but there should be a proper way to disable it
  when running as a virtual machine. And since the splash screen is
  disabled anyway when creating a server virtual machine there is really
  no use in a framebuffer, especially if it slows everything down to a
  crawl. So what to do?

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