Although most normal actions can be performed from the VI or vSphere Client, when troubleshooting an issue with an ESX host you will likely need to access the terminal prompt. If you open an SSH connection to your ESX host and attempt to sign in using “root”, you may receive “permission denied”. Follow the instructions below to enable root login through SSH. Oh and by the way, if you don’t have a good SSH client, PuTTY is the best choice.
From your ESX host console window, hit ALT-F1 to reach the prompt and sign in as root. At the terminal prompt, open the sshd_config file using the following command:
# nano /etc/ssh/sshd_config
Find the line that states “PermitRootLogin” and change the value to yes. Save your file and exit nano (CTRL-O, CTRL-X). Now you will need to restart the SSH daemon.
# service sshd restart
Now attempt to sign in as root from your SSH client.