/proc/sysrq-trigger该文件能做些什么事情呢? 

# 立即重新启动计算机 (Reboots the kernel without first unmounting file systems or syncing disks attached to the system
echo "b" > /proc/sysrq-trigger

# 立即关闭计算机(shuts off the system)
echo "o" > /proc/sysrq-trigger

# 导出内存分配的信息 (可以用/var/log/message 查看)(Outputs memory statistics to the console) 
echo "m" > /proc/sysrq-trigger

# 导出当前CPU寄存器信息和标志位的信息(Outputs all flags and registers to the console
echo "p" > /proc/sysrq-trigger

# 导出线程状态信息 (Outputs a list of processes to the console)
echo "t" > /proc/sysrq-trigger

# 故意让系统崩溃 ( Crashes the system without first unmounting file systems or syncing disks attached to the system
echo "c" > /proc/sysrq-trigger

 

# 立即重新挂载所有的文件系统 (Attempts to sync disks attached to the system)
echo "s" > /proc/sysrq-trigger

# 立即重新挂载所有的文件系统为只读 (Attempts to unmount and remount all file systems as read-only)
echo "u" > /proc/sysrq-trigger

呵呵,此外还有两个,类似于强制注销的功能
e
 — Kills all processes except init using SIGTERM

i
 — Kills all processes except init using SIGKILL