Emc Corporation

Emc IP Holding Company LLC

Eric Olsen

Scott Auchmoody

Jennifer Starling

Scott H Ogata

Emile Snyder

Mark Richter

Jedidiah Yueh

Thomas B Bolt

William Crosby

Robert Ramos

Clint L McVey

In one example, a method includes performing various operations at a backup server. These operations may include receiving, from a node, a request for restoration of a cumulative backup that includes a plurality of partial backups that have been merged together, where the plurality of partial backups includes data from a group of one or more nodes, and the group includes the node. The method further includes checking the cumulative backup to determine whether or not the cumulative backup has been finalized, accessing the cumulative backup when it has been determined that the cumulative backup has been finalized, and restoring the cumulative backup to a target node.

Cumulative backups

In one example, a method for method for backing up data begins when a backup notice is received from a node. In response to the notice, a slot is reserved in an accounting system for storage of a cumulative backup. One or more partial backups are then received and merged with any data present in the slot so as to create or modify a cumulative backup in the slot, where the cumulative backup includes the one or more partial backups and any other data in the slot. Upon receipt of an indication that the cumulative backup is final, the cumulative backup is recorded, and access to the cumulative backup enabled.

In one example, a method may include performance of a hash function on a digital sequence so as to generate a hash value that corresponds to the digital sequence. Next, the digital sequence may be broken into data pieces, and each data piece hashed to produce a corresponding hash value for each data piece. Then, a recipe may be produced that includes instructions which, when executed, may generate the digital sequence from the data pieces referenced by their corresponding hash values included in the recipe. Among other things, the hash values may enable reutilization of redundant data sequences by serving as pointers to the data pieces that the hash values respectively represent.

Storage of data with composite hashes in backup systems

In one example, a method of restoring data backed up in a content addressed storage system may include retrieving a recipe and appended storage addresses from a first storage node of content addressed storage, where the recipe may include instructions for generating a data structure from two or more data pieces, and the two or more data pieces may be resident in locations identified by the appended storage addresses. The example method may further include populating a cache with the appended storage addresses for the two or more data pieces. As well the method may further include retrieving, and populating the cache with, the two or more data pieces without looking up a storage address for any of the two or more data pieces in an index, and restoring the data structure using the retrieved two or more data pieces in the cache.

Restoring data backed up in a content addressed storage (CAS) system

In one example, a system that is operable to back up and restore data may include a high efficiency storage application configured to back up a chunk of data of a client system to a content addressed storage system by generating a recipe that includes instructions for generating the chunk of data from a plurality of data pieces. The system may further include a backup server communicably connected to the high efficiency storage application and configured to, among other things, in response to receipt of a restore request, recover the chunk of data by retrieving the recipe and appended storage addresses in one index seek without separately looking up a storage address for any of the plurality of data pieces in an index.

System for backing up and restoring data

Seek operations required to perform backup and/or restore processes at an HFS server are reduced by localizing storage of data referenced by hash values included in a recipe near the recipe. In a typical embodiment, an HFS server receives a recipe and new underlying data for entry into a hash file system. The HFS server identifies a first storage node for the recipe, contiguously stores the new data in the first storage node, and indexes hash values and storage addresses of the new data in storage nodes selected based on the hash values of the new data. Storage addresses for the new data (and other data referenced by the recipe) are appended to the recipe. Later during a restore process, retrieval of the recipe also retrieves the storage addresses. Data pieces stored contiguously can then be collectively retrieved in one seek rather than in separate individual seeks.

A priority restore agent in a data storage system generates a priority restore data set for a client computer system or device by identifying a set of active data sets and/or a set of key data sets within client system data generated by the client computer system. The priority restore agent looks at or processes file system attributes for the client system data and compares these attributes with predefined restore parameters. The restore parameters may indicate that any file that has been accessed, modified, or created within a particular period of time be included in the priority restore data set. The key data sets may be identified in a set of automated restore rules. A data protection application within the data storage system can restore data in the priority restore data set onto the client computer system after a disaster or system crash.

Automated priority restores

A backup is performed by a client at a time when a backup server is unable to process the backup. The client maintains a cache including a root tag vector and hash entries. The client begins a backup by writing the root tag vector to a journal file and breaking files into pieces. For each piece, the client performs a hash and compares the resulting hash to entries in the cache. If the hash does not match any entries, the client records a request in the journal file to add the corresponding piece of data to an archive. After completing the backup, the journal file can be sent to the server. Before processing the journal file, the server validates the root tag vector. If the root tag vector is valid, the server processes each of the requests to add data. Otherwise, the server discards the journal file.

Growing community of inventors

Lake Forest, CA, United States of America

Eric Olsen