Red Hat Knowledgebase

Single user mode can be accessed by appending an S (the capital letter S) to the kernel command line in GRUB. To do this, restart your system and when the GRUB splash screen presents itself:

1. Select/highlight the kernel you wish to boot using the up/down arrow keys.
2. Press the e key to edit the entry.
3. Select/highlight the line starting with the word kernel.
4. Press the e key to edit the line.
5. Append the letter S to the end of the line.
6. Press ENTER to accept the changes.
7. Press the b key to boot the kernel with the modified command line.

This will take you into single user mode and should provide a bash shell to execute commands.