Hi Edgard,
Sad news. If it's not too late yet for this hint, you may at least slightly reduce the reload time by pre- allocating the database. I'm quite sure that the -dbs option of dbinit was not available with v.9, but the ALTER DBSPACE SYSTEM ADD ... SQL statement definitely was. Enlarging the .db file may help to reduce file level fragmentation and generally makes the LOAD operation faster (by more than the extra time required to run the statement).
HTH
Volker