Messages in this thread | | | Date | Fri, 1 Apr 2011 08:59:38 -0700 | From | Dmitry Torokhov <> | Subject | Re: signal to PID 1 from serial console like KeyboardRequest or CAD |
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On Fri, Apr 01, 2011 at 11:47:10AM -0400, Jeremy Jackson wrote: > On 04/01/2011 11:42 AM, Randy Dunlap wrote: > >On Fri, 01 Apr 2011 11:39:28 -0400 Jeremy Jackson wrote: > > > >>On 04/01/2011 01:37 AM, Dmitry Torokhov wrote: > >>>On Thu, Mar 31, 2011 at 12:57:06PM -0700, Randy Dunlap wrote: > >>>>On Fri, 25 Mar 2011 13:41:40 -0400 Jeremy Jackson wrote: > >>>> > >>>>>Hi, > >>>>> > >>>>>Sent to linux-console with no reply for over a week... > >>>>> > >>>>>I ran into a problem recently on a Linux server with a remote serial > >>>>>console. /sbin/init (actually Upstart) was in a state where nothing > >>>>>(useful) was running. I had to power cycle the machine to get back to > >>>>>the boot prompt. This has the side-effect of triggering raid rebuilds. > >>>>> > >>>>>It would be nice to have what Ctrl-Alt-Del does at the VGA console with > >>>>>PS/2 or USB keyboard. This sends a SIGINT to PID 1, and most distros > >>>>>have this set to do "shutdown -r now" which attempts a clean reboot. > >>>> > >>>>so C_A_D works at console via PS/2 or USB keyboard, but not on a remote > >>>>serial console? Could it be an issue with whatever remote/serial software > >>>>you are using? > >>> > >>>I believe it is simply a matter of console keymap and assigning "boot" > >>>value to the desired combination. > >> > >>The VGA console/keyboard isn't an issue here, C_A_D works great. The > >>problem is, that functionality isn't available when using *serial* console. > > > >That's why I asked whether it could be an issue with the serial interface > >software. E.g., minicom handles/processes certain keystrokes, other apps do things > >differently, etc... > > OK I guess I should clarify... when using Linux serial console, you > can send BREAK <letter> to use SysRq functions.
Ah, right, we hardwire BREAK to SysRq when using serial console...
> In minicom, META-F > sends break. This works fine for all the existing functions linux > offers, r = reboot immediate, i = kill all tasks, etc. But, there > is no function available to reboot *clean*, or to signal PID 1 > (/sbin/init) to do same. So, minicom is working/configured > properly, Linux just doesn't offer a feature similar to C_A_D via > serial.
SysRQ+REISUB should do it I think.
-- Dmitry
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