Magic SysRq Key Sequences over Remote DRAC5 Connection

Adam Nielsen adam.nielsen at uq.edu.au
Sun Jun 6 21:07:58 CDT 2010


> Fixes and Enhancements:
> *SysRq magic key doesnt work on dell systems remotely

Funny, that doesn't show up on the page for me.

> Never mind the missing apostrophe... I've downloaded this release,
> installed it, and don't yet have remote Magic SysRq.
> I'm not quite sure what key sequence to type.  In OpenSSH if I type ~B
> to send a break, I can't be pressing the ALT key at the same time.
> What exactly is Dell thinking will be at the remote end?

You don't need to hold Alt when working over the serial port. 
Alt+PrintScreen on a PC keyboard sends the special SysRq keycode, which 
is replaced by the 'break' on a serial console.   So break+h over serial 
should print the SysRq help message.

~B via OpenSSH doesn't work for me either.  Looking at the source code 
for the 'connect com2' program[1], it seems that it's a simple 'cat' 
from stdin to the serial port, which wouldn't pass through any breaks (I 
think these are sent via ioctls.)  Perhaps this was fixed in the newest 
firmware?  I only have the source up to v1.48 to check.

A better alternative might be to write a program which is run directly 
from the DRAC command line and sends a break + char, then dumps any 
following output.  Sadly Dell haven't released enough of the DRAC code 
to make this possible.

Cheers,
Adam.

[1] 
http://www.shikadi.net/dell/opensource-dvd1/DRAC/DRAC5-1.48/DRAC5-1.48.iso/rac5_open/d5ttyd/connect.c 
which in turn runs
http://www.shikadi.net/dell/opensource-dvd1/DRAC/DRAC5-1.48/DRAC5-1.48.iso/rac5_open/rootsrc/usr/sbin/connect.script



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