Emc Corporation

Emc IP Holding Company LLC

Daniel Ravan

Kiran Bachu

Venu Varma

A system for an efficient data rehydration comprises a server, one or more reader device managers, a writer device manager, and a verifier. The server is for receiving a restore list comprising a plurality of storage locations and lengths for performing a data rehydration. The one or more reader device managers is for reading a data set indicated by the restore list by reading the plurality of storage locations for the lengths from one or more storage nodes. The plurality of storage locations and lengths indicate chunks from a client system stored as part of a full or as an incremental backup session on a storage device attached to a storage node. The writer device manager is for transferring the data set to a save node. A verifier is for verifying transfer of the data set.

Efficient data rehydration

A system and method for efficiently creating a backup volume that is also efficient to recover is described. The backup volume may be created with one save set per media record by utilizing record level multiplexing rather than chunk level multiplexing. Through the use of multiple circular buffers, with each buffer associated with a respective save set, save sets written to storage media are contiguous and individual save set chunks are not separated by chunk headers within the respective media record. Recovery is therefore more efficient since the step of reading chunk headers and locating all the chunks for a save set is no longer required.

System and method for record level multiplexing of backup data to storage media

The invention is a system and method for quickly cloning a backup (file system) volume. Present volume cloning methods are based on creating copies of individual save sets written to a backup volume. However, this requires the steps of reading data blocks to cull the backed up data, stored as data chunks, from the chunk headers that separate and describe each data chunk, then writing the data chunks to new media. As a result, cloning a backup volume is time consuming and tedious. The invention applies the features and benefits of advanced file system devices ('AFTDs') to volume cloning. AFTDs store data as streams, rather than chunks, since AFTDs store data on disk media rather than on tape with tape blocks. As such, data stored on AFTDs are not separated by chunk headers. Instead, an AFTD contains a single volume label file that identifies the AFTD volume. The invention is a system and method for cloning backup volumes stored on AFTDs. Because data on AFTDs does not require separating data chunks from chunk headers, data may be quickly streamed and written from a source AFTD to a destination AFTD. The invention thereby creates a mirror image of the source device more quickly than cloning a tape volume.

System and method for fast volume cloning

Managing access to a shared resource includes receiving a request indicating that an operation requires access to the shared resource, associating the operation with a lock in a lock queue that is associated with the shared resource, and determining whether the shared resource is accessible to the operation.

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Fremont, CA, United States of America

Daniel Ravan