How to Change the Root Password on VMware ESX 3

There are two scenarios in which you would want to change the root password on a VMware ESX server. The first and most common is changing a known password as part of a policy-driven effort to change key system passwords on a scheduled basis. This is widely considered a best practice and is recommended in the VMware Security Hardening Guide.



The second scenario is changing a forgotten root password, a situation that is rare, embarrassing, and inevitable. Fortunately, VMware has recognized that these occasions arise, and has provided a method to reset the root password.

Things You'll Need

• Access to the ESX Service Console

Instructions

Changing a Known Root Password

1. Log in to the ESX host service console.

2. Type "su -" to gain root privileges, if you logged in with an account other than root. You will be prompted for the current root password.

3. Enter the following command:

   passwd root

4. Supply a new root password when prompted. You will be prompted to enter it again to verify that it was typed in correctly.

5. Type "exit" to end your console session.

Changing a Forgotten Root Password

1. Power down or evacuate any virtual machines running on the host.

2. Reboot the ESX host.

3. Arrow down to "Service Console only (troubleshooting mode)" when the GRUB bootloader appears, but do not hit "Enter" to select.

4. Press the "a" key

5. Append the kernel arguments statement by entering a single space and the word "single" and then press "Enter." ESX will continue to boot.

6. When the command prompt appears, enter the following command:

   passwd

7. Type in the new password and hit "Enter." You will be prompted to confirm the password. Type it again and hit "Enter."

8. Type "reboot" and press "Enter."

References

• VMware: Changing an ESX host root password
• VMware: Changing a forgotten root password on an ESX host
• VMware: Security Hardening Guide