Emc Corporation

Emc IP Holding Company LLC

Benoit Joseph Merlet

Benjamin W Yoder

Deepak Vokaliga

Vadim Longinov

George Quill

Mark J Halstead

Madhav Mutalik

Bhaskar Bora

Ananthan K Pillai

Jeffrey Phillips

Ajay Shekhar

John G Deshayes

Eddie Pavkovic

Faith M Senie

Dharmesh Thakkar

Joseph P Russo

Puneesh Chaudhry

Techniques are described for processing multi-page write operations to maintain write level consistency. A multi-page write spanning multiple cache pages is directed to a target device and received on a first data storage system where writes to the target device are synchronously replicated to a second data storage system. On the first data storage system, each of the multiple cache pages may be synchronously replicated to the second data storage system. A lock on each of the cache pages is not released until an acknowledgement is received regarding successful replication of the cache page. On the second data storage system, requests to replicate the multiple cache pages containing write data of the multi-page write are received and processed using locks of corresponding cache pages on the second data storage system. Such techniques also handle concurrent reads and/or writes. Deadlock detection and resolution processing may be performed for concurrent writes.

Maintaining write consistency on distributed multiple page writes

Described are techniques for controlling a flow of I/O requests. R is received denoting a current maximum number of outstanding I/O requests allowed to be issued by a first data storage system to a second data storage system over a path. Assessment processing is performed to obtain a first performance value, a second performance value, and a third performance value, respectively, when the maximum number of outstanding I/O requests allowed to be issued by the first data storage system to the second data storage system over the path is R+delta1, R, and R&#x2212;delta2 (delta1 and delta 2 are positive integer values). It is determined whether to update R in accordance with criteria including the first performance value, the second performance value and the third performance value.

Adaptive and optimized flow control mechanism

This invention is a system and method for a system and method for interfacing with a user for a client application for carrying out backup and restore operations and related configuration. The method includes presenting a user with a user interface for performing a dialogue and using information acquired in the dialogue for performing a configuration or a backup or restore operation.

System and method for configuring and performing application backups and restores in diverse environments

A backup server controls the backing up of data stored on a mass storage subsystem in response to a backup request from a host identifying data to be backed up during a backup operation, the mass storage subsystem storing data in a plurality of mirrored copies. The backup server comprises a discovery module, a preparation module, an execution module and a clean-up module. The discovery module receives the backup request and identifies, during a discovery phase, at least one storage location on the mass storage subsystem on which data to be backed up during the backup operation is stored. The preparation module, during a preparation phase following the discovery phase, enables the mass storage subsystem to sever one of said mirrored copies and make it available to backup server for the backup operation. In addition, prior to enabling the mass storage subsystem to sever one of the mirrored copies, the preparation module will notify the host, which will stop operating in connection with the data from the mass storage subsystem, and after the mirrored copy has been severed, the preparation module will so notify the host so that it can resume operating in connection with data from at least one of the other copies. The execution module, during the execution phase, enables the mass storage subsystem to retrieve data from the at least one storage location and transfer the retrieved data to the backup server to facilitate backup storage. The clean-up module, during a clean-up phase following the execution phase, verifies that the data to be backed up has been stored in backup storage and enable the mass storage subsystem to re-synchronize the mirrored copies. The backup server also performs a restore operation in response to a restore request from the host.

System and method for backing up data stored in multiple mirrors on a mass storage subsystem under control of a backup server

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Chelmsford, MA, United States of America

Benoit Joseph Merlet