A data processing method, a device, and a system for a storage unit in order to avoid performing repeated data read operations on the storage unit where the method includes recording, by a first server for at least one storage unit used to store data, information about a storage unit in which a repairable fault occurs but repairing fails, querying, by the first server each time a request for reading data is received, whether the storage unit corresponding to the recorded information about the storage unit stores a part or all of the data, and when the storage unit corresponding to the recorded information stores the data, returning, to a requesting party that sends the request, a message indicating that reading the data fails, or otherwise, reading the data from a storage unit that stores the data, and feeding back the data to the requesting party that sends the request.