If you have forgotten or don't know the password for the root user on an ESX Server host, you can change it without reinstalling ESX Server.
Note: The procedure below performs a password reset, it "blindly" replaces the existing root password with a new one. This is not password recovery, it does not allow you to learn the original root password.
1. Reboot the ESX Server host.
2. When the GRUB screen appears, press the space bar to stop the server from automatically booting into VMware
ESX Server.
3. Use the arrow keys to select Service Console only (troubleshooting mode).
4. Press the a key to modify the kernel arguments (boot options).
5. On the line presented, type a space followed by the word single .
6. Press Enter. The server continues to boot into single-user mode.
7. When presented with a bash prompt such as sh-2.05b#, type the command passwd and press Enter.
8. Follow the prompts to set a new root user password.
9. When the password is changed successfully, reboot the host using the command reboot and allow VMware ESX Server to boot normally.
EASY, right ?!?!