ORA-12505: TNS:listener does not currently know of SID given in connect descriptor (DBD ERROR: OCIServerAttach)

I have some vague recollections of Oracle databases needing a bit of fiddling when you reboot for the first time after installing the database. However, you haven't given us enough information to work on. To start with:

• What code are you using to connect to the database?
• It's not clear whether the database instance has been started. Can you connect to the database using sqlplus / as sysdba from within the VM?
• What has been written to the listener.log file (in %ORACLE_HOME%\network\log) since the last reboot?

EDIT: I've now been able to come up with a scenario which generates the same error message you got. It looks to me like the database you're attempting to connect to has not been started up. The example I present below uses Oracle XE on Linux, but I don't think this makes a significant difference.

First, let us confirm that the database is shut down:

$ sqlplus / as sysdba

SQL*Plus: Release 10.2.0.1.0 - Production on Sat Jul 17 18:16:43 2010

Copyright (c) 1982, 2005, Oracle.  All rights reserved.

Connected to an idle instance.

It's the text Connected to an idle instance that tells us that the database is shut down.

Using sqlplus / as sysdba connects us to the database as SYS without needing a password, but it only works on the same machine as the database itself. In your case, you'd need to run this inside the virtual machine. SYS has permission to start up and shut down the database, and to connect to it when it is shut down, but normal users don't have these permissions.

Now let us disconnect and try reconnecting as a normal user, one that does not have permission to startup/shutdown the database nor connect to it when it is down:

SQL> exit
Disconnected

$ sqlplus -L "user/pw@(DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=localhost)(PORT=1521))(CONNECT_DATA=(SID=XE)))"

SQL*Plus: Release 10.2.0.1.0 - Production on Sat Jul 17 18:16:47 2010                                                                                                               

Copyright (c) 1982, 2005, Oracle.  All rights reserved.

ERROR:
ORA-12505: TNS:listener does not currently know of SID given in connect
descriptor                                                             


SP2-0751: Unable to connect to Oracle.  Exiting SQL*Plus

That's the error message you've been getting.

Now, let's start the database up:

$ sqlplus / as sysdba

SQL*Plus: Release 10.2.0.1.0 - Production on Sat Jul 17 18:17:00 2010

Copyright (c) 1982, 2005, Oracle.  All rights reserved.

Connected to an idle instance.

SQL> startup
ORACLE instance started.

Total System Global Area  805306368 bytes
Fixed Size                  1261444 bytes
Variable Size             209715324 bytes
Database Buffers          591396864 bytes
Redo Buffers                2932736 bytes
Database mounted.
Database opened.
SQL> exit
Disconnected from Oracle Database 10g Express Edition Release 10.2.0.1.0 - Production

Now that the database is up, let's attempt to log in as a normal user:

$ sqlplus -L "user/pw@(DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=localhost)(PORT=1521))(CONNECT_DATA=(SID=XE)))"

SQL*Plus: Release 10.2.0.1.0 - Production on Sat Jul 17 18:17:11 2010

Copyright (c) 1982, 2005, Oracle.  All rights reserved.


Connected to:
Oracle Database 10g Express Edition Release 10.2.0.1.0 - Production

SQL> 

We're in.

I hadn't seen an ORA-12505 error before because I don't normally connect to an Oracle database by entering the entire connection string on the command line. This is likely to be similar to how you are attempting to connect to the database. Usually, I either connect to a local database, or connect to a remote database by using a TNS name (these are listed in the tnsnames.ora file, in %ORACLE_HOME%\network\admin). In both of these cases you get a different error message if you attempt to connect to a database that has been shut down.

If the above doesn't help you (in particular, if the database has already been started, or you get errors starting up the database), please let us know.

EDIT 2: it seems the problems you were having were indeed because the database hadn't been started. It also appears that your database isn't configured to start up when the service starts. It is possible to get the database to start up when the service is started, and to shut down when the service is stopped. To do this, use the Oracle Administration Assistant for Windows, see here.

I Changed Sid Value to orcl, it works fine and connection established

You could try this.

In windows go to Administrative Tools->Services And see scroll down to where it says Oracle[instanceNameHere] and see if the listener and the service itself are running. You might have to start it. You can also set it to start automatically when you right-click on it and go to properties.