The Solaris 8 Interactive Installation Program mounts the system's file systems onto /a. The file systems remain mounted on /a until the system reboots. Therefore, you can use the finish script to add, change, or remove files from the newly installed file system hierarchy by modifying the file systems respective to /a.
Output from the finish script is deposited in /var/sadm/finish.log.
Ensure that root owns the finish script and that its permissions are set to 644.