root.sh script is written in the orainst directory.
root.sh, which is a shell script, updates/creates an oratab file. The oratab file is the file where the user will place references to all databases to be discovered by the agent and controlled by the Oracle Enterprise Manager. For each database created, the entry is of the form: :<$ORACLE_HOME>:[Y/N]
The agent is normally configured by root.sh as a setuid program. If root.sh was successful, the agent will have been installed as setuid root so that the agent can run jobs as the users whose name and password are given in the Preferred Credentials for that host.
If the agent is not a setuid program, all Enterprise Manager jobs are run with the permissions of the user who started the agent.
The user who submits node jobs to the UNIX agent should have read/write access to the Agent's ORACLE_HOME. If the root.sh does not have setuid set, then any job submitted to the agent will run with the privileges of the user who owns the Agent executable (dbsnmp.exe). root.sh will force the user to set the preferred credentials at the Oracle Enterprise Manager Console for any job on the Agent.