Reboot machine when everything is hanging

<alt> + <print screen/sys rq> + <R> - <S> - <E> - <I> - <U> - <B>
If the machine is hanging and the only help would be the power button, this key-combination will help to reboot your machine (more or less) gracefully. R - gives back control of the keyboard S - issues a sync E - sends all processes but init the term singal I - sends all processes but init the kill signal U - mounts all filesystem ro to prevent a fsck at reboot B - reboots the system Save your file before trying this out, this will reboot your machine without warning! http://en.wikipedia.org/wiki/Magic_SysRq_key

108
By: dizzgo
2009-02-20 07:28:56

What Others Think

doesn't work on fedora ;=s
renich · 503 weeks and 3 days ago
This works! (but here's hoping you don't have to use it. :-)
mpb · 503 weeks and 3 days ago
I think it depends on they keyboard: I haven't had much luck with USB ones. Although debatable, it should also be REISUB. A program could write data when sent the term signal (as that's a clean shutdown command), and not be synced (which is done first), causing the data to lounge around in cache and then vanish. Also, it's worth noting that you should wait a second or two between the U and B, just to make sure that everything has in fact been written to disk.
clockworkavian · 503 weeks ago
mnemonic for REISUB key combination is ; it is reverse of BUSIER
alperyilmaz · 499 weeks and 1 day ago
Well....... This trick will work if and only if you have set some kernel parameter. Interested guys can find out the parameters and post it here. Long days before, I was playing with this and not do not remember the parameters but they are most probably in the "kernel hacking" section ( 2.6.21 ) Good Luck....
Satish · 475 weeks and 2 days ago
Your kernel needs CONFIG_MAGIC_SYSRQ=y
hfs · 471 weeks and 1 day ago
I pressed <alt> + <print screen> + <r> and my computer went into an infinite loop of opening the print screen dialog. WTF?
csmeder · 459 weeks and 3 days ago
it worked for me after i launched otherwise when doing prntscrn i get screenshot window. it not useful when freezing since unless you are in the tty. ubuntu 10.4
firstohit · 432 weeks and 2 days ago
Lovely! I keep a printed version of the Wikipedia article in my desks drawer.
jjj0978yug · 406 weeks and 1 day ago
not working!!!!!!!!!!!!!!!!!!!!!
student · 94 weeks ago

What do you think?

Any thoughts on this command? Does it work on your machine? Can you do the same thing with only 14 characters?

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