Oracle starts OEM or OMS properly

To enable OEM or OMS properly, there are two key points:
1. Whether the Oracle system service is enabled;
2. Are the usernames and passwords used for Logon correct.

First, let's talk about Oracle's system services. In the case of full installation, there are 11 Oracle system services:
1. Oracle OLAP 9.0.1.0.1
2. Oracle OLAP Agent
3. OracleOraHome90Agent
4. OracleOraHome90ClientCache
5. OracleOraHome90HTTPServer
6. OracleOraHome90ManagementServer (0.5 M)
7. OracleOraHome90PagingServer
8. OracleOraHome90SNMPPeerEncapsulator
9. OracleOraHome90SNMPPeerMasterAgent
10. OracleOraHome90TNSListener (5.2 M)
11. OracleServiceORACLE (70 M)
(Note: OraHome90 is the name of the main directory of Oracle that can be changed during installation, and www.bkjia.com is the default value during installation)

The three most important services are OracleOraHome90ManagementServer, OracleOraHome90TNSListener, and OracleServiceORACLE.
Next, let's take a look at the startup errors related to them.
1. Oracle System prompt: Ora-12541: TNS: No listener;
2. The operating system prompts that the OMS service cannot be started on the local computer.
Error: 1053: the service did not respond in time to control the request;
The above two error messages are mostly caused by the OracleOraHome90TNSListener listening service.
Solution: Choose Control Panel> Administrative Tools> services> right-click OracleOraHome90TNSListener and click Start ".

3. Oracle System prompt: Ora-12500: TNS: The Listener cannot start the dedicated server process;
This error is caused by the OracleServiceORACLE dedicated server process.
Solution: Choose Control Panel> Administrative Tools> services> right-click OracleServiceORACLE and click Start ".

4. Oracle System prompt: VTK-1000: Unable to connect to Management Server.
Verify that you have entered the correct host name and status of the Oracle Management Server.
There are two causes for this error: OracleOraHome90ManagementServer has not been started; and host name has not been entered.
Solution: Choose Control Panel> Administrative Tools> services> right-click OracleOraHome90ManagementServer and click Start ",
Or enter the full name of your computer.

Next, let's talk about the username and password used for logon.

After the installation is complete, the SYSTEM provides two default database SYSTEM administrators, whose usernames and passwords are SYS/change_on_install and SYSTEM/manager,
The system also provides the user name and password for logging on to OMS:Sysman/oem_temp. Here, it is prone to errors that the user logs on to OMS using SYS or SYSTEM as the user name,
The Oracle system prompts "Incorrect logon Identity Authentication.

Summary: There is a sequence of starting or disabling these three services.
Generally, OracleOraHome90TNSListener must be started first.
Then start OracleOraHome90ManagementServer or OracleServiceORACLE,
When OracleOraHome90ManagementServer is started, OracleServiceORACLE is also started.

However, you must first disable OracleOraHome90ManagementServer.
Disable OracleOraHome90TNSListener or OracleServiceORACLE,
When you disable OracleOraHome90ManagementServer, if you are prompted to enter the user name and password, enter the user name and password of sysman to ensure successful execution.

If you have other tips, such as resource occupation, I/O duplication, and port usage, contact the system administrator and try again.