Oracle Database Tips by Donald Burleson

Oracle10g Grid Computing with RAC
Chapter 15 - RAC Migration Topics

Manual Conversion Procedure

3. Use the ALTER DATABASE BACKUP CONTROLFILE TO TRACE command to create a control file recreation script in the location specified by the USER_DUMP_DEST initialization parameter.
    

4. Edit the control file recreation script with the REUSE keyword, a specification for MAXINSTANCES (the Oracle suggested setting is 32), MAXLOGFILES and such for a RAC database.
    

5. Next, re-create the control files by executing the script as explained in the script header.
    

6. If the single-instance database is using an SPFILE parameter file, then a temporary PFILE must be created from the SPFILE using the following SQL statement:

CREATE PFILE='pfile_name' from spfile='spfile_name'

(the file names should be full path names)

7. Now shut down the database instance.
    

8. Edit the temporary parameter file and set the CLUSTER_DATABASE parameter to TRUE, and set the INSTANCE_NUMBER parameter to a unique value for each instance, using the sid.parameter=value syntax.
    

9. At this point, the size of the SGA must be adjusted to avoid swapping and paging when you convert to RAC. RAC requires around 350 bytes for each buffer to accommodate the Global Cache Service (GCS). Therefore, if you have 15,250 buffers, RAC requires about 350*15,250 bytes (about 5 meg) more memory. Change the size of the SGA by changing the DB_CACHE_SIZE and DB_nK_CACHE_SIZE parameters accordingly.
    

10. Once the pfile has been edited use it to start up the database instance.
     

11. Once the instance is started, create an undo tablespace for each additional instance using the CREATE UNDO TABLESPACE SQL statement. If you are using raw devices, then ensure that the datafile for the undo tablespace is on a raw device.
     

12. Next, create a new redo thread that has at least two redo logs for each additional instance. If raw devices are being used, then ensure that the new redo log files are also on raw devices. Enable the new redo threads by using the ALTER DATABASE SQL statement.
     

13. Shutdown the database instance using either a shutdown normal or shutdown immediate command.
     

14. Copy the Oracle password file from the source node to the corresponding location on the additional RAC cluster nodes. Make sure that you replace the ORACLE_SID name in each password file name appropriately for each additional instance.
     

15. Edit the pfile and add the REMOTE_LISTENER=LISTENERS_DB_NAME and sid.LOCAL_LISTENER=LISTENER_SID parameters.

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