Emc IP Holding Company LLC

Dell Products Inc.

Yuval Harduf

Xiangping Chen

David Meiri

Chen Reichbach

Ying Hu

Aharon Blitzer

Yuri Alexandrovich Stotski

Aviram Katz

Marina Shem Tov

Nir Sela

Ido Halevi

Tamir Segal

Anton Kucherov

Amitai Alkalay

Alan Lee Taylor

Dmitry Nikolayevich Tylik

Zvi Schneider

Peter John McCann

Nagasimha G Haravu

Felix Shvaiger

Philip C Love

Svetlana Kronrod

Dazhi Dong

Tal Ben-Moshe

Xing Chen

Dmitry Vladimirovich Krivenok

Vitaly Zharkov

Liran Loya

Carole Ann Gelotti

Sally Golan

Venoy Qiang Ma

Kirill Zabelin

Alexander Izikson

Shulamit Katz

A method, computer program product, and computing system for providing on-demand high-availability service on a storage cluster. A new single-node appliance is added to the storage cluster, the storage cluster includes one or more original single-node appliances and an internal remote system configured to facilitate intra-cluster orchestration operation. A remote system object representing the new single-node appliance is generated in the internal remote system. An appliance identifier for the remote system object representing the new single-node appliance is determined. In response to determining that the appliance identifier is a non-zero appliance identifier, an internal remote session between the remote system object and the storage cluster is established. The one or more original single-node appliances and the new single-node appliance are presented as a unified system. Protected storage volumes are provisioned on any of the single-node appliances included in the unified system.

System and method for providing on-demand high-availability service on a storage cluster

Ensuring consistency of data being received by a producer from a collector via a shared memory includes maintaining a time-of-day (TOD) variable, and, by the producer for new data, (1) first setting the TOD variable to an invalid value, (2) next writing the new data into the shared memory with a timestamp, and (3) next setting the TOD variable to a time value corresponding to the timestamp. The method further includes, by the collector for the new data, (1) reading the TOD variable and timestamp and confirming that the TOD variable has a valid time value equal to the timestamp, (2) reading the new data from the shared memory, and (3) confirming validity of the new data by (a) reading the TOD variable again, and (b) confirming that the TOD variable has the same valid time value as in the reading step (1).

Data storage system ensuring consistency of data received by a producer from a collector via a shared memory

A method, computer program product, and computing system for dividing a total IO flow rate limit between a plurality of storage nodes of a multi-node storage system. A total desired IO flow rate may be determined. Each storage node of the plurality of storage nodes may be queried for a desired IO flow rate, thus defining a plurality of desired IO flow rates. An updated IO flow rate limit may be defined, for each storage node, an updated IO flow rate limit based upon, at least in part, the total IO flow rate limit and the plurality of desired IO flow rates. One or more IO requests may be processed on the plurality of storage nodes based upon, at least in part, the updated IO flow rate limit defined for each storage node and the total desired IO flow rate.

Storage management system and method

Techniques for processing commands may include: initially synchronizing a target database of volume reservation and registration information with a source database of volume reservation and registration information; while initially synchronizing the target database with the source database, enabling volume reservation and registration command processing on both a first node managing the source database and a second node managing the target database; while initially synchronizing the target database with the source database, performing first processing to service a first command that is any of a reservation command and a registration command for a first volume; and after initially synchronizing the target database with the source database, using the target database of the second node when servicing reservation and registration commands received at both the first node and the second node.

Techniques for replicating management data

A method, computer program product, and computer system for copying, at a new node, reservation metadata volumes of an old node. While a software upgrade is in progress, volume reservation command processing may be enabled on both the new node and the old node when copying is complete. Separate logic may be run to process a volume reservation command of the volume reservation command processing. The old node may be switched to a primary mode, wherein the new node may be switched to a secondary mode to synchronize volume reservation metadata with a primary copy. When the software upgrade is complete, the new node may be switched to a single mode to use only a volume reservation database of the new node.

System and method for shared volume persistent reservation database for software upgrade

A simulated stretched volume may be configured from multiple volumes of a single data storage system. The volumes may be assigned unique identifiers. The volumes may be exposed to a host over paths from the single data storage system as the same volume having the same unique identifier. The single data storage system may include sets of target ports with each set simulating paths to a different data storage system. A management command may be received that is directed to the simulated stretched volume having the unique identifier. The management command may be received on a path from the host to a target port of the single data storage system. Servicing the management command may include the single data storage system simulating either the local or remote system depending on the set of target ports including the target port.

Simulating stretched volume remote instance using a shadow volume on a local system

A method for use in a storage system is disclosed, comprising: receiving, at a first server in the storage system, a given block layer request for reservation of a storage resource, by the first server, an identifier corresponding to the given block layer request; performing a search of a database to detect whether the given block layer request has been completed, the search being performed by the first server, the search being performed based on the identifier corresponding to the given block layer request; when the database indicates that the given block layer request has not been completed: completing the given block layer request and transmitting a notification that the given block layer request is completed; and when the database indicates that given block layer request has been completed, re-transmitting a notification that the given block layer request is completed.

Transient software error handling in a distributed system

Data storage management may include configuring a stretched volume in a metro cluster configuration using a first volume and a second volume both configured as a same logical volume, L; receiving I/O operations at the metro cluster configuration directed to L, wherein the I/O operations include a write operations that are received at a first system of the metro cluster configuration and that write first data to the first volume; viewing values of a metric regarding data replication performed for the first volume to replicate data between systems of the metro cluster configuration for writes directed to the first volume; responsive to said viewing, determining whether the first metric values denote a problem has occurred in the metro cluster configuration at a first point in time; and responsive to determining that the problem has occurred at the first point in time, performing one or more corrective actions.

Data storage system management techniques and metrics

A method for use in a first storage array, comprising: detecting whether a second storage array has designated the first storage array as a locally-preferred storage array, the detecting being performed when a first link between the second storage array and a witness node is down; setting a value of a first configuration setting to indicate that the first storage array is designated as a system-preferred storage array, the value of the first configuration setting being stored in a memory of the first storage array, the value of the first configuration setting being set only when the second storage array has designated the first storage array as a locally-preferred storage array; detecting, by the first storage array; and when the second link is down, assuming one of an active role or a passive role based, at least in part, on the value of the first configuration setting.

Storage system with passive witness node

A technique manages drive space within a storage system having a main data services environment configured to perform data storage operations on behalf of a set of hosts and a simple data services environment configured to load the main data services environment. The technique involves, while the simple data services environment is running on the storage system, using the simple data services environment to load the main data services environment on to the storage system. The technique further involves, after the main data services environment is loaded on to the storage system, providing a drive space communication from the simple data services environment to the main data services environment. The technique further involves receiving, by the simple data services environment, allocation of drive space from the main data services environment in response to the drive space communication.

Managing drive space among different data services environments within a storage system

An apparatus comprises at least one processing device configured to define a consistency group comprising a plurality of storage volumes subject to replication from a source storage system to a target storage system. In conjunction with a transition from asynchronous replication of the consistency group to synchronous replication of the consistency group, the at least one processing device completes a current asynchronous replication cycle, utilizes a current asynchronous snapshot set on the target storage system to establish an active snapshot set on the target storage system, transfers differential data of a subsequent asynchronous replication cycle to the active snapshot set on the target storage system, specifies the active snapshot set on the target storage system as a destination of the synchronous replication, and performs a data consistency check on the target storage system utilizing an additional snapshot set generated from the active snapshot set.

Storage system with data consistency checking in synchronous replication using active snapshot set

In one aspect, minimization of recovery time after a high availability (HA) event in a storage system is provided. An aspect includes creating, during an active replication session, mini replication session MOM objects from replication session-related configuration information of the active replication session, and creating mini volume objects for volumes of the active replication session, Upon determining an occurrence of the HA corresponding to the data module, an aspect includes reconfiguring the mini replication session MOM objects and the mini volume objects prior to activation of the data module and prior to enabling input/output (TO) servicing by the data module. An aspect further includes performing non-replication IO-related configuration for the data module and, upon completion of the non-replication IO-related configuration, enabling the IO servicing by the data module. Subsequent to enabling the IO servicing by the data module, an aspect also includes loading and reconstructing remaining replication session-related configuration.

Minimizing recovery time after a high availability event in a large-scale storage system

In one aspect, support for hash based xcopy replication for synchronous replication is provided. An aspect includes determining, in response to an xcopy command, whether a source logical unit (LU) and a target LU are in active synchronous replication to the same target site. Upon determining that the LUs are in active synchronous replication, increasing a count of a hash handle list, obtaining a unique full hash digest, and sending the digest with volume replication pairing identifier, offset, and length to the target. Upon receiving a request from the source, searching, by the target, for local hash handles of the digest; and upon determining the local hash handles exist in the digest, incrementing, the reference counter handle list, and sending corresponding hash handles from the source site to the target.

Method to support hash based xcopy synchronous replication

An apparatus in one embodiment comprises at least one processing device comprising a processor coupled to a memory. The processing device is configured to receive a request to write a given data object to a write buffer of at least one storage system, to allocate an entry in the write buffer, to generate a header for the given data object comprising a first portion indicating a validation status, to write the header to the allocated entry of the write buffer with the first portion of the header comprising a value indicating invalid status, to write the given data object to the allocated entry of the write buffer, and to update the header of the allocated entry by modifying the value of the first portion of the header to indicate valid status responsive to a successful write of the given data object to the allocated entry of the write buffer.

Object headers facilitating storage of data in a write buffer of a storage system

Described embodiments provide systems and methods for operating a storage system wherein an online consistent system checkpoint is generated. The checkpoint contains a point in time image of a system and is used for providing recovery of the system to a known good state. In one embodiment the checkpoint includes volume configuration data, logical volume space, a plurality of layers of metadata, and physical data storage.

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Yahud, Israel

Yuval Harduf