Путь
Upgrade your DB2 Version 7 clients to he latest Version 7 FixPak level.
Migrate your DB2 Version 7 servers to ersion 8 and upgrade to the latest FixPak level.
Migrate your DB2 Connect Version 7 servers to Version 8 and upgrade to the latest FixPak level.
Migrate your DB2 clients to Version 8 and upgrade to the latest FixPak level.
Optional - Migrate your server from DB2 Version 8 from 32-bit to 64-bit.

Ограничения

DB2 Version 8 clients can connect to DB2 Version 7 servers only if the DB2 server is running a DRDA Application Server. Refer to the Version 7 Installation and Configuration Supplement for instructions.

There are still numerous restrictions, see the “Version 8 incompatibilities with previous releases” topic in the Information Center for more details:

publib.boulder.ibm.com/infocenter/db2help/index.jsp?topic=/com.ibm.db2.udb.doc/admin/r0008109.htm

DB2 Version 8 clients cannot connect to DB2 Connect Version 7 servers. Upgrade your DB2 Connect servers to Version 8 before you update your DB2 clients to Version 8.

No restrictions in connecting DB2 Version 7 32-bit clients to DB2 Version 8 32-bit servers

No support for Version 7 32-bit clients connecting to DB2 Version 8 64-bit server.

No support for attach from Version 7 32-bit to Version 8 any bit

publib.boulder.ibm.com/infocenter/db2help/topic/com.ibm.db2.udb.doc/start/r0009731.htm