Sometimes we need to reboot remote machine. But all we get an error in console.
The most popular reason of this disk problems. To perform force rebooting turn on SRK feature in the kernel via proc VFS:
# sysctl -w kernel.sysrq=1
and send command to kernel to reboot the system without unmounting file systems:
echo b > /proc/sysrq-trigger
Here is some additional SRK features:
• r — Disables raw mode for the keyboard and sets it to XLATE (a limited keyboard mode which
does not recognize modifiers such as Alt, Ctrl, or Shift for all keys).
• k — Kills all processes active in a virtual console. Also called Secure Access Key (SAK), it is
often used to verify that the login prompt is spawned from init and not a trojan copy designed to
capture usernames and passwords.
• b — Reboots the kernel without first unmounting file systems or syncing disks attached to the
system.
• c — Crashes the system without first unmounting file systems or syncing disks attached to the
system.
• o — Shuts off the system.
• s — Attempts to sync disks attached to the system.
• u — Attempts to unmount and remount all file systems as read-only.
• p — Outputs all flags and registers to the console.
• t — Outputs a list of processes to the console.
• m — Outputs memory statistics to the console.
• 0-9 — Sets the log level for the console.
• i — Kills all processes except init using SIGKILL.
• l — Kills all processes using SIGKILL (including init). The system is unusable after issuing this SR Key pre.
• h — Displays help text.
