Single User Mode - Password Recovery

Use single user mode to assist in troubleshooting system boot issues or for password recovery.

To enter single user mode:

  1. Boot the switch, then as soon as you see the GRUB menu, use the arrow keys to select Advanced options for Cumulus Linux GNU/Linux.

    Before the GRUB menu appears, the switch goes through the boot cycle. Do not interrupt this autoboot process when you see the following lines; wait until you see the GRUB menu.

    ...
    CLOCKS:ARM Core=1000Hz, AXI=500Hz, APB=125Hz, Peripheral=500Hz
    USB0:  Bringing USB2 host out of reset...
    Net:   eth-0
    SF:    MX25L6405D with page size 4 KiB, total 8 MiB
    Hit any key to stop autoboot:  2
    

                 GNU GRUB  version 2.02+dfsg1-20
    
    +----------------------------------------------------------------------------+
    |*Cumulus Linux GNU/Linux                                                    |
    | Advanced options for Cumulus Linux GNU/Linux                               |
    | ONIE                                                                       |
    |                                                                            |
    +----------------------------------------------------------------------------+
    
  2. Select Cumulus Linux GNU/Linux, with Linux 4.19.0-cl-1-amd64 (recovery mode).

                 GNU GRUB  version 2.02+dfsg1-20
    
    +----------------------------------------------------------------------------+
    | Cumulus Linux GNU/Linux, with Linux 4.19.0-cl-1-amd64                       |
    |*Cumulus Linux GNU/Linux, with Linux 4.19.0-cl-1-amd64 (recovery mode)       |
    |                                                                            |
    +----------------------------------------------------------------------------+  
    
  3. Press ctrl-d to reboot.

  4. After the system reboots, set a new root password. The root user provides complete control over the switch.

    root@switch:~# passwd
    Enter new UNIX password:
    Retype new UNIX password:
    passwd: password updated successfully
    

    You can take this opportunity to reset the password for the cumulus account.

       root@switch:~# passwd cumulus
       Enter new UNIX password:
       Retype new UNIX password:
       passwd: password updated successfully
    

  5. Sync the /etc directory, then reboot the system:

    root@switch:~# sync
    root@switch:~# reboot -f
    Restarting the system.