Dell Switch S4128T run with OS10 password recovery

OS10(config)# system-user linuxadmin password Dell@Force10!@
OS10(config)# exit
OS10# write memory

If you lose both OS10 user and Linux admin passwords so that you cannot log in to the CLI, you must recover the linuxadmin password from GRUB:

1. Connect to the serial console port. The serial settings are 115,200 baud, 8 data bits, and no parity.
2. Reboot or power up the system.
3. Press ESC at the Grub prompt to view the boot menu. The OS10-A partition is selected by default.

   +-------------------------------------+
   |*OS10-A |
   | OS10-B |
   | ONIE |
   +-------------------------------------+
   

4. Press e to open the OS10 GRUB editor.
   1. Use the arrow keys to navigate to the end of the line that has set os_debug_args= and then add init=/bin/bash.

      +---------------------------------------------------------+
      |setparams 'OS10-A' |
      | |
      | set os_debug_args="init=/bin/bash" |
      | select_image A |
      | boot_os |
      | |
      +---------------------------------------------------------+
      

5. Press Ctrl + x to reboot your system. If Ctrl + x does not cause the system to reboot, press Alt + 0. The system boots to a root shell without a password.
6. At the root prompt, enter usermod -s /bin/bash linuxadmin to enable the linuxadmin user.

   root@OS10: /# usermod -s /bin/bash linuxadmin

7. Verify  the linuxadmin password status by entering the passwd -S linuxadmin command.

   If the password is locked, L is displayed following linuxadmin in the command output. Unlock the password by entering the passwd -u linuxadmin command.

   root@OS10:~# passwd -S linuxadmin
   linuxadmin L 10/01/2018 0 99999 7 -1
   
   root@OS10:~# passwd -u linuxadmin
   passwd: password expiry information changed.

8. If the OS10 version is 10.5.1.0, then run the following command.

   root@OS10: /# sed -ibak '31,41s/^/#/g' /opt/dell/os10/
   bin/recover_linuxadmin_password.sh

9. Configure the password by using the /opt/dell/os10/bin/recover_linuxadmin_password.sh plain-password command. Enter the linuxadmin password in plain text.

   root@OS10: /# /opt/dell/os10/bin/recover_linuxadmin_password.sh Dell@admin0!@

10. Enter the sync command to save the new password.

    root@OS10: /# sync

11. Reboot the system, and then enter your new password.

    root@OS10: /# reboot -f
    Rebooting.[ 822.327073] sd 0:0:0:0: [sda] Synchronizing SCSI cache
    
    [ 822.340656] reboot: Restarting system
    
    [ 822.344339] reboot: machine restart
    BIOS (Dell Inc) Boot Selector
    S6010-ON (SI) 3.20.0.3 (32-port TE/FG)
    
    Reset Dell OS10 Password - YouTube
    
    Hope that helps!