Rebooting Linux Magically

If you have ever had a filesystem fail on you in Linux then you are quite aware of that “bottom of the pit” feeling you get in your stomach, especially if you are remote to the server and have no physical access to it. What to do if the system can’t load the reboot or shutdown binaries to reboot your system and have fsck save your butt.

magic SysRq key is a feature built in to the kernel that lets you preform a number of interesting operations inculding rebooting a system. You can issue keystrokes to the magic SysRq device in /proc so you can send a hard reboot directly to the kernel with no disk access required.

[Link to Linux Journal article on rebooting via SysRq]

Frank's the editor in chief of tech.nocr.at. He can be found surfing the internet and playing with gadgets. Follow him on twitter @franklinhares