A junk directory identification method and apparatus. The junk directory identification method comprises: obtaining a directory to be identified; wherein, the directory to be identified is a directory generated after running of an application software; obtaining the file names of the files in the directory to be identified; determining whether the file names of the files in the directory to be identified all conform to temporary file naming rule; if so, determining the directory to be identified as a junk directory. Hence, the present solution uses a method of determining whether the file names of the files in the directory to be identified all conform to the temporary file naming rule to identify whether a directory to be identified is junk file, making full use of the unique naming method when a directory automatically created by a software application caches files, and can therefore effectively identify whether a directory in an application software is a junk directory.

A hybrid data management/storage system is provided which includes two or more integrated or connected data management systems. An external application and/or user interacts with the hybrid data management/storage system using a unified interface. Incoming raw data may be directed to be stored in any of a plurality of data management systems based on the incoming data object having one or more of a number of predefined characteristics, including for example size and/or data type. Metadata corresponding to all incoming data objects may be stored in a particular data store, regardless of whether the incoming object's raw data is stored in a different one of the plurality of data stores.

Cloud units in cloud storage include containers including data containers storing file segments, segment tree containers storing upper-level segments of segment trees representing the files, and cloud containers storing headers from the data and segment tree containers. A header for a data container includes fingerprints identifying the file segments. A header for a segment tree container includes fingerprints identifying the upper-level segments. A storage appliance stores a first level of metadata for each cloud unit in a read-write state, a second level of metadata for each cloud unit in a read-only state, and a third level of metadata for each cloud unit in an offline state. The third level requires less storage than the first and second levels. The second level requires less storage than the first level. The limited metadata space of the appliance is managed by maintaining at least a subset of cloud units in the read-only state.

Disclosed are various embodiments for applying a pruning to data sets, files, logs, and/or any other information. A binning methodology may be employed to determine which data to retain or discard to determine a resulting set of data resembling an exponential decay where more recent items of data are more likely to be retained and more archaic items of data are more likely to be discarded. The resulting set of data may be associated with an average age.

An electronic device is provided. The electronic device includes a storage, and a processor configured to execute a storage device manager function, when the storage device manager function is executed, check a free space on a file system, as a result of the checking of the free space, determine whether the free space of the storage is less than or equal to a first reference ratio, when the free space of the storage is less than or equal to the first reference ratio, select and compress data having a use frequency less than or equal to a predetermined use frequency, manage the compressed data by using a list, and reserve and process a block secured by the compression on the file system.

Cloud units in cloud storage include containers including data containers storing file segments, segment tree containers storing upper-level segments of segment trees representing the files, and cloud containers storing headers from the data and segment tree containers. A header for a data container includes fingerprints identifying the file segments. A header for a segment tree container includes fingerprints identifying the upper-level segments. A storage appliance stores a first level of metadata for each cloud unit in a read-write state, a second level of metadata for each cloud unit in a read-only state, and a third level of metadata for each cloud unit in an offline state. The third level requires less storage than the first and second levels. The second level requires less storage than the first level. The limited metadata space of the appliance is managed by maintaining at least a subset of cloud units in the read-only state.