major.io words of wisdom from a systems engineer

Corrupt /dev/null

If you find that /dev/null is no longer a block device, and it causes issues during init on Red Hat boxes, you will need to follow these steps to return things to normal:

  • Reboot the server
  • When grub appears, edit your kernel line to include init=/bin/bash at the end
  • Allow the server to boot into the emergency shell
  • Run the following three commands
# rm -rf /dev/null
# mknod /dev/null c 1 3
# chmod 666 /dev/null

You should be back to normal. Make sure that the root users on your server don’t use cp or mv with /dev/null as this will cause some pretty ugly issues.