Tuesday, February 23, 2010

The Magic SysRq Key

My netbook hangs about once a day. I can now reboot it more easily, thanks to the magic SysRq key.

I'm not sure why it hangs, and I'm not very worried about it. Netbook releases are new, and I remember the same kinds of problems when Linux notebooks were new. I had one laptop that worked perfectly except for sound, the mouse, and networking. :-) The next release fixed all those. (Even now, I have a pair of old notebooks running Jaunty Jackalope because Karmic Koala won't run their fans. They overheat and shut themselves off within minutes.)
I even remember the problems when Unix PCs were new. I was in Dave Barach's living room, in 1983, when he got a call from our Maryland office, which had just received the editor Dave had sent them for our as-yet-unreleased PC/IX product, done under contract to IBM, which was to run on stock IBM PC/XTs.
I could only hear Dave's side of the conversation.
What do you mean, "The color's wrong"? What do you mean, "color"?
We'd never seen a PC with a color monitor. Weren't all displays monochromatic? Once we found out how they worked, Dave fixed the problem.
I am, however, discomfitted by having to power-cycle a box -- I worry about unsynced disks and stuff. Luckily, some neuron fired and I remembered the magic SysRq key. I have had to use it so little, over the years, that I didn't remember any details, but Wikipedia came to my rescue. It does the trick, and lets me do a soft re-boot from my keyboard.

(My keyboard doesn't actually have a key labelled "SysRq," but Alt-"Print Scrn"-k works just as well.)

No muss, no fuss, no bad blocks. Magic.

Thrupence and sixpence every day.


jed said...

Alt-"Print Scrn"-k ?

One would think you were using Emacs.

FWIW, I've never had SysRq work. Even back when I was runing RH8 or something like that. I do recall something about how it's disabled in Ubuntu, and I haven't ever gotten around to whatever it is I'm supposed to do to make sure it's enabled. But then, once I was reminded that not all is sweetness and light in the world of OpenGL drivers, and turned off the screensavers that use it, I haven't had a hang. (Knock on silicon)

Was something on /. a while back about Lenovo (?) getting rid of the SysRq key. So I guess having an Emacsian chord is handy.

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