Reset Password if forget username and password Follow

Example: Reset Password

Reference model:

• Switch model name: All
• Edgecore SONiC version: All

Procedure :

Step 1: Reboot system and press “e” to edit SONiC grub option (e.g SONiC-OS-Edgecore-SONiC_20201123_130028_ec202006_74)

                             GNU GRUB  version 2.02~beta3

 +----------------------------------------------------------------------------+
 |*SONiC-OS-Edgecore-SONiC_20201123_130028_ec202006_74                        |
 | ONIE                                                                       |
 |                                                                            |
 |                                                                            |
 |                                                                            |
 |                                                                            |
 |                                                                            | 
 +----------------------------------------------------------------------------+

      Use the ^ and v keys to select which entry is highlighted.          
      Press enter to boot the selected OS, `e' to edit the commands       
      before booting or `c' for a command-line. 

                             GNU GRUB  version 2.02~beta3
 +-----------------------------------------------------------------------------+
 |setparams 'SONiC-OS-Edgecore-SONiC_20201123_130028_ec202006_74'              |
 |                                                                             |
 |        search --no-floppy --label --set=root SONiC-OS                       |
 |        echo    'Loading SONiC-OS OS kernel ...'                             |
 |        insmod gzio                                                          |
 |        if [ x = xxen ]; then insmod xzio; insmod lzopio; fi                 |
 |        insmod part_msdos                                                    |
 |        insmod ext2                                                          |
 |        linux   /image-Edgecore-SONiC_20201123_130028_ec202006_74/boot/vmli\ |
 |nuz-4.19.0-6-2-amd64 root=UUID=3ec4cab4-38b0-473d-a1ef-0a667f144c1e rw cons\ |
 |ole=tty0 console=ttyS0,115200n8 quiet                  net.ifnames=0 biosde\ |
 |vname=0                 loop=image-Edgecore-SONiC_20201123_130028_ec202006_\ |v
 |74/fs.squashfs loopfstype=squashfs                                       ap\ |
 |parmor=1 security=apparmor varlog_size=4096 usbcore.autosuspend=-1 pcie_asp\ |
 |m=off tg3.short_preamble=1 tg3.bcm5718s_reset=1                              |
 |        echo    'Loading SONiC-OS OS initial ramdisk ...'                    |
 |        initrd  /image-Edgecore-SONiC_20201123_130028_ec202006_74/boot/init\ |
 |rd.img-4.19.0-6-2-amd64 |
+-----------------------------------------------------------------------------+ 
     Minimum Emacs-like screen editing is supported. TAB lists 
     completions. Press Ctrl-x or F10 to boot, Ctrl-c or F2 for 
     a command-line or ESC to discard edits and return to the GRUB menu.

Step 2: Add init=/bin/bash as shown below, 

 +-----------------------------------------------------------------------------+
 |setparams 'SONiC-OS-Edgecore-SONiC_20201123_130028_ec202006_74'              |
 |                                                                             |
 |        search --no-floppy --label --set=root SONiC-OS                       |
 |        echo    'Loading SONiC-OS OS kernel ...'                             |
 |        insmod gzio                                                          |
 |        if [ x = xxen ]; then insmod xzio; insmod lzopio; fi                 |
 |        insmod part_msdos                                                    |
 |        insmod ext2                                                          |
 |        linux   /image-Edgecore-SONiC_20201123_130028_ec202006_74/boot/vmli\ |
 |nuz-4.19.0-6-2-amd64 root=UUID=3ec4cab4-38b0-473d-a1ef-0a667f144c1e rw cons\ |
 |ole=tty0 console=ttyS0,115200n8 init=/bin/bash quiet   net.ifnames=0 biosde\ |
 |vname=0                 loop=image-Edgecore-SONiC_20201123_130028_ec202006_\ |v
 |74/fs.squashfs loopfstype=squashfs                                       ap\ |
 |parmor=1 security=apparmor varlog_size=4096 usbcore.autosuspend=-1 pcie_asp\ |
 |m=off tg3.short_preamble=1 tg3.bcm5718s_reset=1                              |
 |        echo    'Loading SONiC-OS OS initial ramdisk ...'                    |
 |        initrd  /image-Edgecore-SONiC_20201123_130028_ec202006_74/boot/init\ |
 |rd.img-4.19.0-6-2-amd64                                                      |
 +-----------------------------------------------------------------------------+ 
      Minimum Emacs-like screen editing is supported. TAB lists 
      completions. Press Ctrl-x or F10 to boot, Ctrl-c or F2 for 
      a command-line or ESC to discard edits and return to the GRUB menu. 

Note: This insertion will be restored after rebooting. Therefore, it's not necessary to edit grub option again.

Step 3: Press Ctrl+x to boot

Loading SONiC-OS OS kernel ...
Loading SONiC-OS OS initial ramdisk ...
[ 2.708038] irq 16: nobody cared (try booting with the "irqpoll" option)
[ 2.714804] handlers:
[ 2.717210] [<ffffffff94c427b0>] serial8250_interrupt
[ 2.722539] Disabling IRQ #16
[ 3.647833] ixgbe 0000:08:00.1: HW Init failed: -17
bash: cannot set terminal process group (-1): Inappropriate ioctl for device
bash: no job control in this shell
root@(none):/#

Step 4: Now you're able to modify the password by linux command.  Username root as example. 

root@(none):/# passwd root
Enter new UNIX password:
Retype new UNIX password:
passwd: password updated successfully

Step 5: Reboot the switch by linux command or Power cycle the switch

root@(none):/# reboot -f

Reference: SONiC Github https://github.com/Azure/SONiC/blob/master/doc/SONiC-User-Manual.md#23-how-to-reset-password