1. Start and stop the Oracle management agent.
>emctl start agent (stop)
The database as separate entities and not within the centralized Grid Control framework, issue the     emctal start dbconsole. (stop)

2. Using iSql*Plus
>isqlplusctl start (stop)

Obtaining a List of Ports Used by the Oracle Components
To view a summary of which ports are in use by the various Oracle components, you can view the portlist.ini file. This file is normally located in the $ORACLE_HOME/install directory on Unix or %ORACLE_HOME/install directory on Windows. Here is an example of what you might see in the portlist.ini file:
Ultra Search HTTP port number =5620
Enterprise Manager Agent Port =
iSQL*Plus HTTP port number =5560
Enterprise Manager Console HTTP Port (orcl) = 5500
Enterprise Manager Agent Port (orcl) = 1830
Enterprise Manager Console HTTP 端口 (ORL) = 1158
Enterprise Manager 代理端口 (ORL) = 3938

Four accounts are preconfigured when you set up your database:
SYS The SYS user owns all the internal Oracle tables that constitute the data dictionary. Normally, you should not perform any actions as the SYS user and should ensure that this account is locked down. Also, don’t manually modify the underlying objects owned by the SYS user.
SYSTEM SYSTEM is an additional support user that contains additional administrative tablesand views. This account should also be locked down to prevent unauthorized use of it.
DBSNMP DBSNMP is a login used by the Enterprise Manager facility to monitor and gather performance statistics about the database.
SYSMAN SYSMAN is the equivalent of the SYS user for the Enterprise Manager facility. This Enterprise Manager administrator can create and modify other Enterprise Manager administrator accounts, as well as administer the database instance itself.

Storage Options

File System Storage
File system storage is the most common type of storage configuration for pre–Oracle 10g databases. This type of storage definition relies on the underlying operating system to maintain and manage the actual files that you as the DBA define. When you choose this option, the DBCA suggests a set of datafile names and directory locations for those files. You can modify this information at a later step in the database creation process.
The DBCA uses the Optimal Flexible Architecture (OFA) directory design for laying out the suggested file locations. The OFA is an Oracle-recommended method for designing a flexible directory structure and naming convention for your Oracle database files.
ASM Storage
Automated Storage Management (ASM) is a new type of storage mechanism available in Oracle 10g. ASM is designed to relieve the burden of disk and storage management and relies on Oracle to maintain your database storage. Instead of your managing many individual database files, ASM allows you to define disk groups for file management.
Using disk groups, you can define one or more groups of disks as a logical unit that Oracle views as a single unit of storage. This concept is similar in nature to the way that some operating systems, including various flavors of Unix, define volume groups.
Oracle manages the storage definitions of the database within a second database used exclusively by ASM to keep track of the disk group allocations. When you create a database and select the ASM option in the Storage Options screen, a series of screens guides you through the process of defining the secondary ASM database instance.
Raw Devices
You can also select a raw device as your storage definition. Raw devices are disks that are not managed by the underlying operating system. Instead of the underlying operating system controlling disk reading and writing activities, Oracle performs the actions directly to the underlying hardware without handing the responsibilities off to the operating system.
Typically, the systems administrator predefines the raw disk partitions that will constitute the specific raw devices. Then, you as the DBA map the raw devices to specific datafiles and redo log files.

STARTUP [NOMOUNT|MOUNT|OPEN] [PFILE/SPFILE=] [RESTRICT]