Tue Mar 08, 2005 12:24 am
Tue Mar 08, 2005 12:46 am
Tue Mar 08, 2005 1:51 am
Tue Mar 08, 2005 3:51 am
Tue Mar 08, 2005 8:11 am
unclekyky wrote:a little off topic but what does the SysRq even do?
VeraX wrote:The Print Screen key you have to press doesn't say Print Screen. It says
Prt Sc
SysRq
Wed Mar 09, 2005 8:17 am
Thu Mar 10, 2005 7:46 am
Hunter Lupe wrote:unclekyky wrote:a little off topic but what does the SysRq even do?
It's rather disused. The Linux kernel uses it as a priority command -- you can invoke several commands by pressing the SysRq key in combination with others.
Try a google search?VeraX wrote:The Print Screen key you have to press doesn't say Print Screen. It says
Prt Sc
SysRq
That depends on the keyboard. I've seen some where it's labeled as Print Screen. Mine reads PrtScn SysRq Insert.
Thu Mar 10, 2005 9:00 am
unclekyky wrote:a little off topic but what does the SysRq even do?
The Magic SysRq Key
This feature allows you to do some basic maintenance tasks even if the rest of the system isn't responding. In particular, it allows you to shutdown your system properly, thus avoiding the risk of file system corruption when simply turning the machine off with media still being mounted.
The 'SysRq' sequence involves pressing three keys at once, theleft ALT key, the 'SysRq' key (also labeled 'PrtSc' or 'F13') and a letter key:
1. <ALT> <SysRq> <r> puts the keyboard in 'raw' mode.
This might be helpful in cases where the graphical interface does not respond to keyboard or mouse commands any more. Having pressed that sequence, press <ALT> <CTRL> <BACKSPACE> simultaneously. This will try to kill the X server and drops you onto the console (i.e. it's the emergency key combination to switch from runlevel 5 to runlevel 3).
2. <ALT> <SysRq> <s> attempts to write all unsaved data to disk ('sync' the disk) to prevent file corruption.
3. <ALT> <SysRq> <e> sends a termination signal to all processes, except for 'init'.
4. <ALT> <SysRq> <i> sends a kill signal to all processes, except for init, thus terminating all processes which ignored the termination signal.
5. <ALT> <SysRq> <u> remounts all mounted file systems read-only. This prevents file system corruption.
6. <ALT> <SysRq> <b> reboots the system. Alternatively, replace the 'b' with an 'o' to turn the machine off.
If you look at this sequence, you see that you are - apart from the first step - actually emulating the 'init' shutdown process. Therefore it is important that you press these sequences in the correct order (e.g. that you 'sync' the drives before remounting them): Raw -Sync - tErm - kIll -Umount - reBoot.
Thu Mar 10, 2005 11:29 am