It is mandatory that the user ID of the user who runs the installation is same as Admin server user ID. Before you install Sun Java System Web Server, you must log in as root, unless you meet the following conditions:
You plan to install the Sun Java System Web Server on a port higher than 1024.
The location where you plan to install the server (the server root directory) is writable with your non-root login.
You are not planning to use Express installation.
If you meet these conditions, you do not need to log in as root to install the server; instead log in as the user account that the Administration Server will use. However, you may still prefer to log in as root, even though you meet the conditions.
Only root can bind to ports >= 1024. However, to improve security, do not allow an instance to run as root. You can configure an instance to run as another user. By default, an instance's configuration files are writable by the user that instance runs as. This means a non-root user can modify an instance's configuration file to obtain root access. Therefore, to further improve security, avoid starting an instance as root.
Solaris offers the net_privaddr privilege to allow specific non-root users to bind to ports lesser than 1024. Using this privilege means even instances that bind to ports lesser than 1024 can be started by non-root users.