Provided are a computer program product, system, and method for determining a storage pool in which to store a data object. Event messages are received. Each event message includes metadata on an object updated in a storage pool of a plurality of storage pools, at least two of the storage pools have different reliability ratings. The event messages are added to a message queue. A determination is made of a data classification of a changed data object indicated in an event message in the message queue. The changed data object is moved to a storage pool having a reliability rating satisfying a reliability rating associated with the data classification of the changed data object.