Emc IP Holding Company LLC

Emc Corporation

Mohd Fahadullah

Eric Michael Lemar

Justin Husted

Asif Arif Daud

Matthew D Fleming

Mayank Rajawat

Sandeep Joshi

Barry Naujok

Vikrama Reddy

Kamal J Charan

Prasad Krishnan

Ronald Stuart Steinke

The described technology is generally directed towards domains that data services can use to collect files of a global filesystem namespace into groups. A data service (a domain patron) creates a domain, e.g., for a particular directory, and a domain manager associates files under that directory with domain membership information. Thereafter, the data service can use the domain membership information associated with a file to determine whether to include that file in a data service operation. In one implementation the membership information is maintained in file metadata, facilitating fast and efficient retrieval of the information in near constant time. Exclusion from a domain, hard links, renames and alternate data streams are among the various aspects supported by the domain technology.

Partitioning a distributed filesystem namespace

Implementations disclosed herein provide for cauterizing portions of a snapshot. A file and/or directory or a set of files and directories of a snapshot can be identified via a user request or an automated process for cauterization. When cauterized, if a previous snapshot does not contain a ditto entry to the portion of the current snapshot that is requested to be cauterized, the BADDR associated with the cauterized portion of the snapshot can be freed for other storage use. In some implementations, metadata associated with the data that is cauterized can be retained for other uses.

Snapshot cauterization

Embodiments are directed towards cloning files in a distributed file system. In response to a request to create file clones, a file cloning application can be employed to generate file clones based on a source file. The file cloning application can generate a new inode for each new file clone and at least one new shadow store. Data blocks from the source file can be transferred to the shadow store. The transferred data blocks can be replaced with reference blocks that point to the data blocks transferred to the shadow store. Likewise, additional reference blocks pointing to data blocks in the shadow store can be generated for the new file clone inodes. Further, the shadow store can maintain reference counters that track the number of reference blocks pointing to each shadow store block. Also, file clones can be generated based on a point-in-time snapshot of the source file.

File clones in a distributed file system

Growing community of inventors

Seattle, WA, United States of America

Mohd Fahadullah