How to reset the lost or forgotten root password in vCenter Server ?

 Process to Reset the Root Password in VCSA:

1. Connect SSH to VCSA 6.7 and login using administrator@vsphere.local where vsphere.local is your default SSO Domain. ​​​​​

• If disabled, enable SSH using the VAMI ( https://<vcenter_fqdn>:5480 ).
• Can login as administrator@vphere.local or any other member of the SSO administrators group.
• Enable or Disable SSH and Bash Shell Access.

2. If first time logging in, enable shell then enter shell.

• shell.set --enable true
• shell

3. Once in shell as sso-user, run the below command to change to root shell.

• sudo -i
• Alternately, you could use the command: sudo passwd root

4. Then once in root shell, run passwd to change the root password.

• passwd

5. Now you can exit the session by running the exit or logout command and then log in through a new SSH session using your root account with updated password. Alternatively, you could run the su command in order to be prompted for the root password and get access as root.