For others visibility. This query works for me. 
 
SELECT DISTINCT STORAGE.name, STORAGE.dataCenter AS DC, STORAGE.family, DATEDIM.fullDate AS Date,sum(STORAGE_FACT.CapacityMB) AS CapacityMB, sum(STORAGE_FACT.usedCapacityMB) AS usedCapacityMB 
FROM storage_dimension STORAGE, date_dimension DATEDIM, storage_and_storage_pool_capacity_fact STORAGE_FACT
WHERE 
STORAGE_FACT.storageTk=STORAGE.tk AND 
STORAGE.dataCenter IN('DC1','DC2','DC3') AND 
DATEDIM.tk=STORAGE_FACT.dateTk AND 
DATEDIM.fullDate>(DATE_ADD(CURDATE(),INTERVAL -30 DAY)) AND
GROUP BY STORAGE.name, DATEDIM.fullDate
Thanks