Content-aware data recovery method for elastic cloud storage

A method for avoiding recovery and storage of useless data is disclosed. The operations comprise: determining that a subset of data fragments out of a plurality of data fragments have become unavailable, the plurality of data fragments forming a data chunk, wherein the plurality of data fragments are protected by additional redundancy data; determining whether all of data that were stored in the unavailable subset of data fragments when the unavailable subset of data fragments were available would be useless if recovered using remaining available data fragments of the data chunk and the redundancy data; and in response to determining that all of the data that were stored in the unavailable subset of data fragments would be useless if recovered, generating new redundancy data for protecting the remaining available data fragments of the data chunk without recovering the data that were stored in the unavailable subset of data fragments.