[ Thanks to idaashley for this link.
]
“Previous to DB2 for Linux, UNIX, and Windows Version 8, SAP
customers could only have one copy of DB2 for each DB2 version
installed on the same physical machine, because the installation
path was hard coded. Although DB2 Version 8 provided an alternative
fix pak image, these images were only used for testing purposes,
and they were not supported in production by SAP.“With DB2 9, customers can install multiple DB2 software copies
on one physical machine. The database installations are independent
of each other. They can be of different levels and installed on any
valid path. Each copy can be updated without affecting the others.
This option is available and supported for all SAP releases as of
R/3 3.1I with DB2 9. In addition, starting with SAP NetWeaver 7.1,
the SAP installer fully explores this feature and installs DB2
software in the home directory of the instance owner…”