There are a few default passwords that should be changed when you first get your Accelerator. This is how to change them via the command line.
Log in to your accelerator over ssh.
Run:
passwd
And you'll be prompted for your current password (supplied by Joyent), and your new password.
As the admin user, run:
sudo passwd root
You will not be prompted for the current password, but asked to enter in your new one.
Log in to MySQL:
mysql -u root -p
You'll be prompted for your MySQL password, supplied by Joyent. Once at the MySQL prompt, run this command:
SET PASSWORD FOR root@localhost=PASSWORD('yournewpassword');
MySQL should return a string like the following:
Query OK, 0 rows affected (0.05 sec)
You can then type quit to exit the command line MySQL interface.
.mysql_history file to remove the entry that shows your password.
Run this command:
sudo /opt/webmin-1.380/changepass.pl /etc/webmin admin yournewpassword
And that should allow you to change the password from the command line.
.bash_history file to remove the entry that shows your password.
There is also probably a way to change the password from within webmin.
If you changed the password of MySQL or PostgreSQL, and you care of any Webmin or Virtualmin functionality, you'll need to update both modules configuration in Webmin so that it has access. Just login to Webmin, switch your view to the Webmin pane, click MySQL or PostgreSQL and follow the 'Module Config' option on the top for a form that will let you enter the new root password for the service.