Abstract: A method, system and computer-readable medium for providing rapid failback of a computer system is described. The method, which operates during failback of a secondary computer to a primary computer, accesses a map to determine a location of a latest version of data corresponding to a read request, where the location may be within either a primary data storage or a secondary data storage. The system comprises a primary computer coupled to a primary data storage and a secondary computer coupled to a secondary data storage. The primary computer maintains a write log and the secondary computer maintains a map. The computer-readable medium contains instructions, which, when executed by a processor, performs the steps embodied by the method.

Abstract: The embodiments herein relate to data management and, more particularly, to global deduplication and encryption of data in data management systems. The user equipments (UE) are grouped under certain deduplication groups based on certain parameters such as rate of data exchange, frequency of data exchange, social closeness, work closeness, similarity of data and interests and so on, between those UEs. Further, specific deduplication and encryption parameters such as encryption method, encryption key, signature computation method, block computation method and so on are assigned to each group. Further, deduplication and encryption of data in each group is performed using the deduplication and encryption modes and parameters assigned to each group. The deduplication and encryption of data is performed in at least one of the UEs and/or a server. Further, the parameters used for deduplication and encryption are stored in specific databases and are encrypted for better security.

Abstract: Various methods and systems for performing cascaded replication are disclosed. For example, one method involves receiving an acknowledgment at a primary replication site from an intermediate replication site. The acknowledgment identifies whether a change has been applied to a remote replication site. The method also involves updating a journal, in response to the acknowledgment. The journal identifies whether the change is currently being replicated. The method can also involve detecting that the intermediate replication site is inaccessible. In response, the method synchronizes a copy of application data at the remote replication site by applying one or more changes identified in the journal to the copy of the application data at the remote replication site.

Abstract: A method, system, computer system, and computer program product to quickly synchronize replicas of data stored at multiple secondary nodes upon failure of a primary node. Secondary nodes to which an update to data in a region of a storage area is sent are identified. When all of the secondary nodes have acknowledged the update, a notification is sent to each of the secondary nodes. Respective indicator(s) (e.g., “outstanding update” or “out of sync” indicators) can be set to indicate that the data have changed in respective region(s) at one of the secondary nodes when the update has been received at that secondary node. The indicator(s) can be reset for the respective region(s) when the notification sent by the primary node is received at the secondary node. Data in the region(s) can be synchronized with data at secondary nodes when either node has an indicator set for that region.

Abstract: The embodiments herein relate to data management and, more particularly, to global deduplication and encryption of data in data management systems. The user equipments (UE) are grouped under certain deduplication groups based on certain parameters such as rate of data exchange, frequency of data exchange, social closeness, work closeness, similarity of data and interests and so on, between those UEs. Further, specific deduplication and encryption parameters such as encryption method, encryption key, signature computation method, block computation method and so on are assigned to each group. Further, deduplication and encryption of data in each group is performed using the deduplication and encryption modes and parameters assigned to each group. The deduplication and encryption of data is performed in at least one of the UEs and/or a server. Further, the parameters used for deduplication and encryption are stored in specific databases and are encrypted for better security.

Abstract: A method, system and computer-readable medium for providing rapid failback of a computer system is described. The method, which operates during failback of a secondary computer to a primary computer, accesses a map to determine a location of a latest version of data corresponding to a read request, where the location may be within either a primary data storage or a secondary data storage. The system comprises a primary computer coupled to a primary data storage and a secondary computer coupled to a secondary data storage. The primary computer maintains a write log and the secondary computer maintains a map. The computer-readable medium contains instructions, which, when executed by a processor, performs the steps embodied by the method.

Abstract: Applications executing on various nodes in a distributed storage environment may write data to primary storage and may also replicate the data to secondary storage via a replication target. An interval coordinator may coordinate the periodic saving of checkpoints or snapshots of the replicated data. The interval coordinator may determine the length of consistency intervals between the saving of each of the checkpoints. Writes to the replication target from each of the nodes may be associated with the current consistency interval and, in some embodiments, with a unique per-node sequence number. When transitioning between consistency intervals, each node may be configured to temporarily suspend completion of the writes and to send the replication target a consistency interval marker indicating that the node has completed all writes for the current consistency interval.

Abstract: Data-object-level replication is performed based on storage-device-level change tracking. A method of replicating a data object (such as a file) involves accessing mapping information and change information. The mapping information identifies that one or more regions of a storage device (such as a logical volume) store portions of the data object. The change information identifies whether the regions of the storage device, which were identified by the mapping information, have been modified subsequent to a particular point in time. If the change information identifies that any of those regions of the storage device have been modified, replication of each modified one of the regions to a secondary system is initiated. Replication can be initiated from a system other than the production system.

Abstract: A method, system and computer-readable medium for providing rapid failback of a computer system is described. The method, which operates during failback of a secondary computer to a primary computer, accesses a map to determine a location of a latest version of data corresponding to a read request, where the location may be within either a primary data storage or a secondary data storage. The system comprises a primary computer coupled to a primary data storage and a secondary computer coupled to a secondary data storage. The primary computer maintains a write log and the secondary computer maintains a map. The computer-readable medium contains instructions, which, when executed by a processor, performs the steps embodied by the method.

Abstract: Various methods and systems for synchronizing replicas using a single change map are disclosed. One method involves detecting a write to a first region of a volume, while synchronization of the volume with a replica volume is ongoing. If the first region is unsynchronized with respect to a corresponding region of the replica volume, replication of the write is inhibited. Otherwise, the write is replicated. Writes for which replication is inhibited will be applied to the replica volume at a later time as part of the ongoing synchronization.

Abstract: A computer system that implements a method for creating a virtual snapshot of a first storage object. A first storage object such as a data volume is created, wherein creating the first storage object includes creating a first storage object description. This first storage object description relates the first storage object to underlying first storage objects or first physical memory regions. After creating the first storage object, a virtual copy of the first storage object is created as a second storage object. Creating the second storage object includes creating a second storage object description, wherein the second storage object description relates the second storage object to the first storage object. The first storage object is transmitted to a first computer system, and the second storage object description is transmitted to a second computer system.

Abstract: A method, apparatus, and computer program product for setting and implementing a policy to compress the history of data on a temporal volume is described.

Abstract: Various systems and methods are disclosed for storing one or more point-in-time images of data stored in a block device in a sparse file. In one embodiment, a method involves identifying a block of data within a block device and copying the block of data to a sparse file. The block of data is identified in response to being modified. The sparse file stores an incremental image of data stored in the block device. In addition to storing an incremental image, sparse files can be used to store full images. Furthermore, a sparse file can store multiple images (full and/or incremental) of data stored in a block device.

Abstract: A method, system, and computer-readable medium to quickly synchronize copies of data that have diverged over time. The present invention can be used in synchronizing replicated copies of data that have become unsynchronized due to the restoration of primary data from a backup copy of the primary data. The solution enables copies of data to be synchronized without copying all of the data from one copy to another. The solution uses minimal resources to maintain data consistency and has minimal effect on performance of applications using the data and on network usage. The method includes determining that a change occurred to data in a region of a primary volume without including the region in a set of regions designated for replication to a secondary volume. The region is added to the set of regions designated for replication to the secondary volume and replicated.

Abstract: Methods, systems, and computer program products to provide temporal storage in a fabric-based virtualization environment are presented. Such capacity is provided through the association of a temporal storage appliance, which is configured as a member of a linked VLUN with a non-temporal disk volume. The linked VLUN is provided by a virtualizing fabric switch to a network node such as a network node.

Abstract: A system and to prevent data corruption due to split brain in shared data clusters includes two or more nodes of a cluster, a shared storage device, and an update manager. The update manager may be configured to maintain a local persistent store corresponding to each node of the cluster. On receiving an update request directed to the shared storage device from a first node, the update manager may be configured to redirect the update to the local persistent store corresponding to the first node. The update manager may be further configured to verify a cluster membership status of the first node, and to transfer the contents of the update from the local persistent store to the shared storage device if the cluster membership verification succeeds.

Abstract: One method of updating a change track map involves resetting a mirror recovery map for a data volume. Just before the mirror recovery map is reset, a change track map for the data volume can be updated, using the mirror recovery map. The mirror recovery map can be reset by a data element of a data processing system, while the change track map can be updated by a control element of the data processing system.

Abstract: Disclosed is an apparatus and method for transforming unrelated data volumes into related data volumes. The present invention is employed after creation of first and second unrelated data volumes. In one embodiment, the second data volume is refreshed to the data contents of the first data volume so that the second data becomes a PIT copy of the first data volume. Refreshing the second data volume includes overwriting all data of the second data volume with data copied from the first data volume. However, before all data of the second data volume is overwritten with data copied from the first data volume, data of the first data volume can be modified.

Abstract: A computer system that implements a method for creating a virtual snapshot of a first storage object. A first storage object such as a data volume is created, wherein creating the first storage object includes creating a first storage object description. This first storage object description relates the first storage object to underlying first storage objects or first physical memory regions. After creating the first storage object, a virtual copy of the first storage object is created as a second storage object. Creating the second storage object includes creating a second storage object description, wherein the second storage object description relates the second storage object to the first storage object. The first storage object is transmitted to a first computer system, and the second storage object description is transmitted to a second computer system.

Abstract: A system for volume replication in a distributed block virtualization environment includes a first and a second set of one or more physical block devices, a first and a second volume server, one or more volume clients, and a replication manager. The first volume server may be configured to aggregate storage in the first set of one or more physical block devices into one or more logical volumes, and to make the one or more logical volumes accessible to the one or more volume clients. The replication manager may be configured to operate in cooperation with the first and second volume servers and the one or more volume clients to maintain a replica of at least a subset of the one or more logical volumes at the second set of one or more physical block devices.