EXP FAILING EXP-00003: no storage definition found for segment(3, 2)

[sambavan]

It looks like the problem is in your roll back segment 3.

Run the following querry and confirm it

        select * from dba_rollback_segs;

Check all the storage definitions.

        Select * from dba_rollback_segs 
              where segment_id = 3;

Does it look like the rest?

If different look at the segment_name. Try taking that segment off-line.

         alter rollback segment  segment_name offline; 

            select status from dba_rollback_segs 
                 where segment_name = 'SEGMENT_NAME';

It must be OFFLINE.
Then drop that rollback segment. Re-try your FULL export. If the ROLLBACK segment will not go offline, then export using USERS.

Sam