二 SysRq的使用
SysRq的命令键有
'r' - Turns off keyboard raw mode and sets it to XLATE.
'k' - Secure Access Key (SAK) Kills all programs on the current virtual
console. NOTE: See important comments below in SAK section.
'b' - Will immediately reboot the system without syncing or unmounting
your disks.
'o' - Will shut your system off (if configured and supported).
's' - Will attempt to sync all mounted filesystems.
'u' - Will attempt to remount all mounted filesystems read-only.
'p' - Will dump the current registers and flags to your console.
't' - Will dump a list of current tasks and their information to your
console.
'm' - Will dump current memory info to your console.
'0'-'9' - Sets the console log level, controlling which kernel messages
will be printed to your console. ('0', for example would make
it so that only emergency messages like PANICs or OOPSes would
make it to your console.)
'e' - Send a SIGTERM to all processes, except for init.
'i' - Send a SIGKILL to all processes, except for init.
'l' - Send a SIGKILL to all processes, INCLUDING init. (Your system
will be non-functional after this.)
'h' - Will display help ( actually any other key than those listed
above will display help. but 'h' is easy to remember :-)
在终端上同时按Alt, SysRq和命令键则会执行SysRq命令, SysRq键就是"Prent Screen"健. 比如Alt+SysRq+b则重启机器.
如果使用telnet 或ssh连接到服务器则可以使用echo '' > /proc/sysrq-trigger的方式执行SysRq命令, 比如echo 'b' > /proc/sysrq-trigger重启系统.