1. A method of modifying a client-side repository usable for restore operations in a de-duplicated storage system, the method comprising: populating the client-side repository with a plurality of data blocks, the data blocks corresponding to at least a portion of data that is copied from a client system to secondary storage according to a deduplication scheme; populating the client-side repository with deduplication signatures corresponding to the data blocks that are stored in the client-side repository; for at least one restore operation in which at least some of the copied data is restored to the client system: using one or more processors and at least in part based on the deduplication signatures stored in the client-side repository, determining which of the plurality of data blocks are stored in the client-side repository; and accessing the client-side repository to restore the data blocks that are stored in the client-side repository from the client-side repository to the client system, wherein the data blocks that are not stored in the client-side repository are restored from the secondary storage to the client system; generating a metric relating to the usage of the client side repository; and modifying a parameter associated with the client-side repository in response to the performance metric.