Okay... On AIX you can get clustered filesystem using either IBM HACMP or Veritas HA. Both are very expensive. As an alternative in Oracle 10g you can use Oracle CRS and ASM combination. ASM uses RAW devices but presents them as filesystem for Oracle database (only). Starting from 10g2 you have asmtool to browse this filesystem.

Your data migration strategy will depend on how much down time you can afford. It can be CTAS across a database link, replication, transportable tablespace, RMAN, export/import, or OS cp command.

If you do a little of RTFM on tahiti.oracle.com you will be able to find a detailed migration plan in Oracle Database Upgrade Guide book.

Good luck.

Sergey