Michel, ADSM does support databases larger than 2GBs.  Each data file
must be less than 2GB, but the total size of the database can be greater
than 2GB.  DB2/6000 uses ADSM's API, so you just use the normal DB2
backup utilities but choose to direct the output to ADSM.  Both online
and offline backup are supported, and with the current DB2 version only
full database backups are supported.  The new version of DB2/6000, Version 2,
will provide tablespace level backups.  There is documentation on DB2/6000's
use of ADSM in the latest DB2/6000 Administration Guide, and I'm in the
final stages of finishing a redbook on using ADSM to Back Up Databases....
Cyndie Behrens
IBM - ITSC San Jose
cbehrens AT vnet.ibm DOT com