Insurance against system malfunction is provided by the kernel compile option
"Magic SysRq key". Pressing Alt-SysRq on an i386, followed by one of
the keys r 0 k e i s u b, does the magic.
Un`r'aw restores the keyboard after things like X crashes. Changing the
console loglevel to `0' reduces error messages. sa`k' (system attention key)
kills all processes on the current virtual console. t`e'rminate kills all
processes on the current terminal except
init. k`i'll kills all
`S'ync, `u'mount, and re`b'oot are for getting out of really bad situations.
Debian default installation kernels are not compiled with this option at the
time this document is written. Recompile the kernel to activate this function.
Detailed information is in