Abstract: Described are techniques for performing data storage management. A first data portion is stored at a first logical address of a first device that is mapped to a first physical storage location at which the first data portion is stored. A second data portion is stored at a second logical address on a second device that is mapped to a second physical storage location at which the second data portion is stored. The first data portion is a duplicate of data contents of the second data portion and the first physical storage location is the same physical storage location as the second physical storage location. The first device and the second device are thin devices where physical storage is unallocated for at least a portion of each thin device's storage capacity at a point in time.

Abstract: Migrating data from an old storage device to a new storage device includes creating new paths to the new storage device, freezing old paths to the old storage device, transferring metadata corresponding to the old storage device to the new storage device, where state information is transferred from the old storage device to the new storage device, and thawing the new paths. Migrating data from an old storage device to a new storage device may also include creating new volumes on the new storage device and transferring data from the old storage device to the new storage device. Migrating data from an old storage device to a new storage device may also include dismantling the old paths.

Abstract: A method, system, and computer program product for ordering a plurality of data IO captured at a primary site to be applied at a secondary site, comprising removing the one or more extent level portions from the captured data IO, determining if the one or more extent level portions are time sequenced to overwrite a portion of data of the data IO, based on a determination that the portion data is to be overwritten, removing the overwritten portion of data from the plurality of the data IO and ordering the one or more extent level portions to be applied at the secondary site before the captured data IO.

Abstract: Described are techniques for performing dynamic binding of device identifiers to data storage devices. A first device identifier assigned to an application on a host is received. The first device identifier is a unique detachable device identifier dynamically bound to different data storage devices at different points in time in accordance with data storage devices used by the application. The first device identifier is attached to a first data storage device of the data storage system used by the application at a first point in time. The first device identifier is detached from the first data storage device thereby making the first data storage device unavailable for data operations from the application. The first device identifier is attached to a second data storage device used by the application at a second point in time thereby making the second data storage device available for data operations from the application.

Abstract: A computer-implemented method of ordering data writes includes at least some of a plurality of primary storage devices receiving a first plurality of data writes and causing a cycle switch for the plurality of primary storage devices. The first plurality of data writes are associated with a particular cycle on each primary storage device in the plurality of primary storage devices. At least some of the plurality of primary storage devices receive a second plurality of writes after initiating the cycle switch. All of the second plurality of writes are associated with a cycle different from the particular cycle on each of the plurality of primary storage devices.

Abstract: A method, system, and program product for data replication comprising, building a virtual image of a point in time in a Data Protection Appliance (DPA), taking a storage array based snapshot of a current image, creating a hot pull session and exposing a LUN containing the point in time image at the DPA.

Abstract: Sharing at least one link among a plurality of processes includes determining a capacity of the at least one link based on a number of I/O operations per unit time supported by the at least one link as a function of the amount of data provided by each of the I/O operations, determining a requirement of each of the processes based on user specifications and an amount of data provided by each I/O operation for each of the processes, and apportioning link capacity among the processes according to the requirement of each of the processes. In response to a sum of requirements for each of the processes being less than the capacity of the at least one link, additional link capacity may be provided to at least some of the processes.

Abstract: Described are techniques for performing processing in a data storage system. A client application executing on a host is identified as a candidate for migration to the data storage system. First data used by the client application is stored on one or more physical storage devices of the data storage system. The client application is migrated to the data storage system for temporary execution on the data storage system. The client application is executed on the data storage system for a time period using a first portion of resources of the data storage system allocated for exclusive use by migrated client applications executing on the data storage system.

Abstract: A method for scanning a message-list accessible to a plurality of processors includes retrieving, from a cache associated with a scanning processor from the plurality of processors, information identifying a starting message-slot. This information is then used to begin a scan of the message-list at that starting message-slot. The information indicating the starting message-slot is obtained by identifying, in the message-list, a message-slot containing a message intended for a recipient processor from the plurality of processors and obtaining, from the identified message-slot, information indicative of a location of a succeeding message-slot in the message-list. This information is then cached, for retrieval during a subsequent scan of the message-list.

Abstract: Reversing a communication path between a first volume on a first storage device and a second volume on a second storage device includes suspending communication between the first and second volumes while maintaining operations for other volumes of the storage devices, causing the first volume to change from a source volume to a destination volume without destroying the first volume, causing the second volume to change from a destination volume to a source volume without destroying the second volume, and resuming communication between the first and second volumes. Causing the first volume to change from a source volume to a destination volume may include modifying a table of the first storage device. Causing the second volume to change from a source volume to a destination volume may include modifying a table of the second storage device.

Abstract: Handling asynchronous data provided by at least two sources includes synchronizing data between the at least two sources, coordinating cycle switching between the at least two sources, where an asynchronous cycle of data from one of the sources corresponds to an asynchronous cycle of data from an other one of the sources, receiving asynchronous data corresponding to a data cycle from at least one of the sources, and saving at least some of the received data. A first portion of data for a particular cycle may be transmitted from one of the sources and a second portion of data for the particular cycle, different from the first portion of data, may be transmitted from an other one of the sources and the first portion and the second portion together may correspond to all of the data for the particular cycle.

Abstract: In one aspect, a method includes providing a first storage volume to receive I/Os from a host and having a device ID, providing a second storage volume to receive the I/Os and having a device ID and performing a recovery that includes rebooting the host and recognizing, at the host, the second storage volume as the first storage volume using the device ID of the second storage volume being identical to the device ID of the first storage volume. The first storage volume is in an active mode and the second storage volume is in a passive mode.

Abstract: The disclosure relates to a method and system for creating a virtual array in a physical array. Unassigned whole volumes in at least one physical array are identified. The identified volumes are associated with a first virtual array. Unique names are given to the identified volumes. At least one path is assigned to the first virtual array. The first virtual array may be associated with a second virtual array. Data may be migrated or replicated from the first virtual array to the second virtual array using existing array services.

Abstract: Methods and apparatus for eliminating the need for a complete synchronization due to failure of a data protection appliance in a continuous data protection system having a replication splitter. In one embodiment, a continuous data protection system includes a source side having a source side storage array with a splitter and a data protection appliance, where processing includes initiating a source side splitter session, initializing a first I/O tracking mechanism for the splitter session, and activating the splitter to a source side processing active state to continuously push I/O data from the source side to the target side.

Abstract: Continuous backup from a local storage device to a remote storage device includes subdividing the local storage device into subsections, providing a time indicator that is modified periodically, and, in response to a request to write new data to a particular subsection of the local storage device at a particular time, maintaining at the remote storage device data being overwritten by the new data according to the particular subsection and according to a value of the indicator at the particular time. Providing continuous backup from a local storage device to a remote storage device may also include restoring the local storage device to a state thereof at a particular point in time by writing the maintained data to the remote storage device and transferring the data from the remote storage device to the local storage device.

Abstract: Migrating data from an old storage device to a new storage device includes transferring the data from a first logical device on the old storage device to a second logical device on the new storage device, determining replication relationships for the first logical device, transferring the replication relationships; and transferring logical devices used for the replication relationships from the old storage device to the new storage device. The replication relationships may include a clone of the first logical device. Migrating data from an old storage device to a new storage device may also include suspending writes to the first logical storage device prior to transferring the data for the first logical storage device. The replication relationships may include at least one snapshot.

Abstract: A system for managing distributed storage includes a collection of one or more compute sites that are connected and that perform a joint computation. A witness node is connected to the one or more compute sites. A membership service allows a change in collection membership, in response to a failure, to continue the joint computation without causing data inconsistency or corruption. If the membership service is unable to reach a decision on the change in collection membership in response to the failure, the witness node controls the decision on the change in collection membership to continue the joint computation. A distributed storage system provided by the system described herein may advantageously meet consistency guarantees and maximize data access even when individual compute sites and/or their interconnects fail.

Abstract: Migrating data from an old storage device to a new storage device includes creating new paths to the new storage device, freezing old paths to the old storage device, transferring metadata corresponding to the old storage device to the new storage device, where state information is transferred from the old storage device to the new storage device, and thawing the new paths. Migrating data from an old storage device to a new storage device may also include creating new volumes on the new storage device and transferring data from the old storage device to the new storage device. Migrating data from an old storage device to a new storage device may also include dismantling the old paths.

Abstract: Methods and apparatus for storage snapshots for logged access replication using a data protection appliance in a continuous data protection system having a splitter. In one embodiment, out of band data transfer reduces disruption on the replica site while accessing an image.

Abstract: Methods and apparatus for a continuous data protection system having a protection agent and at least one data protection appliance that enables, in an image access mode, a rolling back of volumes in a highly available storage array on the target side so that the volumes contain data for a selected point in time, creation of a storage array snapshot of the volumes for the point in time, and user access to the storage array snapshot in the storage array.