关键词: 元数据，数据迁移，内容寻址存储，两阶段检索，内容感知

Abstract: As the storage capacity approach Exabytes, how to efficiently organize, find and manage data is becoming increasingly difficult for us. The query requests in storage system are coming from two aspects, the first one is metadata retrieval delivered by administrator and the second one is user's common keyword query. But the functions of de-duplication and block similarity detection in content aware storage system are not utilized to enhance the above query processing. In order to take advantage of the upper semantic information and the lower storage system's duplicate block information to deliver efficient query service for users, a two-phrase retrieval strategy was introduced. It combined metadata/keyword query with block similarity query and utilized ranking coefficient to evaluate similarity among query resups. The experiments indicate that the retrieval strategy has efficiently enhanced the retrieval recall.

Key words: Metadata, Data migration, Content addressable storage, Two-phrase retrieval, Content aware