1. A method implemented by at least one metadata server, comprising: determining that a server of a plurality of servers has failed; determining tracts of data stored on the failed server; determining other servers of the plurality of servers also storing the tracts of data, the tracts of data being distributed among the other servers; and instructing the other servers to write the tracts of data to additional servers to create replicas of the tracts of data, at least two of the other servers performing the writing in parallel.