Oracle 11g's em won't start

A few days ago, on the test server, install an ERP system simulation environment.

In the process of installing Oracle, I encountered the Oracle's EM unreachable, today tossing a morning, finally solved.

Symptoms: Just loaded Oracle 11G, is accessible, after a period of tossing (because it is a test machine, so it is also exported), this morning I want to enter the EM, indicating that it is inaccessible.

Cause unreachable: I don't know.

Toss process:

1, open IE, enter: http://localhost:1158/em, prompt cannot access!!!

Idea: Em didn't start?

2, the command line, input: Emctl start Dbconsole

TIP: Environment variable ORACLE_SID not defined. Please define it.

Idea: Server SID?

3. Input: Set oracle_sid=orcltest01 (orcltest01 is my database name)

No hint,

4, then enter: Emctl start dbconsole

Tip: oc4j Configuration issue. D:/oracle/product/11.2.0/dbhome_1/oc4j/j2ee/oc4j_dbconsole
_HOSTNAME_ORCL not found.

Idea: No files found?? How did you get in yesterday? What the hell ...? I didn't change the IP and the computer name.

5, enter: D:/oracle/product/11.2.0/dbhome_1/oc4/j2ee directory,

Copy the Oc4j_dbconsole_hostname_orcl folder, paste it into the same directory, change the folder name to: OC4J_DBCONSOLE_NC-YYCC_ORCL, where NC-YYCC is the computer name of the machine

6. Enter: D:/oracle/product/11.2.0/dbhome_1 directory

Copy the Hostname_orcl folder, paste it into the same directory, and change the folder name to: NC-YYCC_ORCL

7, try to start, enter the command line, enter: Emctl start dbconsole

TIP: Environment variable ORACLE_SID not defined. Please define it.

.................... I want to cut my hands ...

8. Set oracle_sid=orcltest01

No hint

9, Emctl start Dbconsole

............... Finally successfully started .....

The cause of the unreachable is still not found .....

Oracle 11g's em won't start