SysRq
Sometimes the system seems flaky in responding to the Magic SysRq. I found that if you learn to press the keys as described below then it is perfectly reliable. Think about it like this
Press and hold the Alt key during the entire process. Just press it first; hold it in; and now don't worry about it. Now you just need to press two additional keys in sequence. Press-then-release the SysRq button; then press-then-release the command key. Finally, you can release the Alt key.
Output will not go to an X terminal. It will be printed on the console. Press Ctrl=Alt-F1 to switch view to the console.
One some keyboards (especially Microsoft), you may find a key called "F Lock". This is a stupid key. It's almost like they added a new CapsLock key except that there is no indicator to show that it is turned on. Often you need to press this once before you start. If you switch to a text console you may find that you cannot switch back to the X Window platform. Press F Lock once again to restore the function of the function keys.
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SysRq output
The output of SysRq is logged to the console. If you have debugging set very low then you might not see anything. You can run `dmesg` to see the output or you can increase log visibility by using a SysRq command. Press the following keys to set log visibility to a high level
Alt SysRq 9
Send SysRq without keyboard
You can bypass the keyboard magic keys simply be writing the command code that want to execute to the following file:
echo h > /proc/sysrq-trigger
Enable / Disable SysRq
Enable, write a 1. To disable, write 0:
echo 1 > /proc/sys/kernel/sysrq
Freezing and unfreezing
Notes
Note: Sometimes called SysReq and Sys Request.
