Upgrading ASM to Oracle 11g Oracle 11g New Features Tips by Burleson Consulting July 8, 2008

Oracle 11g SQL New Features Tips

When upgrading from Oracle database 10g to 11g, it comes in very handy to have installed the 10g Oracle software two times in two different ORACLE_HOME directories, an ASM_HOME and a DB_HOME. This is the recommended best practice if  ASM is being used because it makes one independent when it comes to upgrading. The reason why is that it is possible to have an 11g database use ASM disk groups which are managed by a 10g ASM instance and vice versa.

Therefore, just those 10g databases can be upgraded to 11g which are running applications that have already been certified for 11g and the others can remain on 10g until their applications are certified as well while still using the same ASM disk groups as before. In this case, it would be sensible to upgrade the ASM_HOME to 11g, which would cause downtime for all instances depending on the ASM instances running from this home.

After this, all database instances, the 10g as well as the 11g, could use the ASM disk groups managed by the now upgraded Oracle 11g ASM instance. It would then be possible to convert the managed disk groups to 11g compatibility as soon as all databases using them have been upgraded to 11g as well. From this moment on, all databases could profit from the 11g New Features for ASM.

The difference between the relationships of database instances with ASM instances in 10g and 11g is the format of the messages sent between each other and the format of the metadata which describe the disk groups. The format of these messages determines which ASM features can be used by a database. The format of the metadata determines which features a disk group can handle. A third factor which needs to match is the value of the initialization parameter COMPATIBLE of the DB instance as well the ASM instance. This is something that cannot be worked around when upgrading the ASM version in a single instance environment.

 

This is an excerpt from the new book Oracle 11g New Features: Expert Guide to the Important New Features by John Garmany, Steve Karam, Lutz Hartmann, V. J. Jain, Brian Carr. You can buy it direct from the publisher for 30% off.