[Leaplist] Rebooting a frozen box

[Andrew]

On Sep 11, 2007, at 11:11 AM, David Simmons wrote:

> and it even works!
>
> http://fosswire.com/2007/09/08/fix-a-frozen-system-with-the-magic- 
> sysrq-keys/

A couple of things not mentioned in this article:

1) This doesn't _ALWAYS_ work.  There are ways in which the kernel  
can crash where even these sysrq tricks do not work.  For those  
cases, nothing beats a good remote accessible PDU.

2) It is possible to disable this.  Check the state of sysrq via  
`cat /proc/sys/kernel/sysrq` 1 == enabled, 0 == disabled. (Handy for  
kiosks or public terminals.)

3) There are other tricks sysrq can do.  http://en.wikipedia.org/wiki/ 
Magic_SysRq_key has a nice concise listing of them. "p" and "t" were  
pretty handy to get a feel for what was going on when the system got  
into a bad state.

Andrew