If you are new systems administrator in your organisation and you need to log on the console of ESX Host. Previous systems admin didn’t left any documentation what’s so ever. Here is the way to reset root password.
1. Restart the ESX host
2. At the main bootloader screen where it states “Press Tab to toggle
verbose mode” – press shift+O
This is O for orange on the keyboard, not 0 for zero on the keyboard. This
enters the “Enter Advanced Options” session
3. Type the option passwdReset=TRUE
Advanced options piped to the interactive shell like this are case-sensitive.