My PC, running Ubuntu from a live CD, is frozen. I think it's because I have too many Firefox tabs open, which is overloading my memory. Is there anyway to use Magic SysRq to only kill Firefox? Or to switch workstations or something to try and restore functionality?

  • Have you tried Ctrl+Alt+F1 and running killall firefox?
    – Kaz Wolfe
    Aug 15, 2014 at 6:37
  • Ctrl+Alt+F1 doesn't work. Should I use a Magic SysRq to regain keyboard access and then try Ctrl+Alt+F1?
    – Rayman
    Aug 15, 2014 at 18:57

1 Answer 1


No. The nearest thing you can do is use Alt + SysRQ + K which should kill all processes in current VT (in this case it should mean firefox, all graphical programs you were running, your WM and X itself). Then you should be able to switch to another console (using Ctrl + Alt + F[1-6] and run another instance of X from there (I don't use Ubuntu, but I'd bet there is a startx script for that).

SysRQ enables you to do only very "violent" and massive things: shutdown immediately (o), reboot immediately (b), kill everything except init (i), remount all filesystems as readonly (u) ... You probably see that a single letter is not enough to convey the "killall -9 firefox" command.

  • Ok thanks. Then SysRq won't be much use to me because the whole point of this is to recover unsaved files that are still open.
    – Rayman
    Aug 15, 2014 at 19:29
  • You're welcome. If you cannot switch VTs using Ctrl + Alt + F[1-6], then I'm afraid I cannot help you. I have no experience with Live CDs and this issue seems to be connected just with liveCDness of your system :(
    – Ramillies
    Aug 15, 2014 at 19:38

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