Abstract: A method is used in managing data relocation in storage systems. Data access activity information is gathered for a set of slices of a storage tier in a data storage system for migrating the set of slices from the storage tier to another storage tier. The data storage system includes a first storage tier and a second storage tier configured such that performance characteristics associated with the first storage tier is superior to the second storage tier. Based on a pattern indicated by the data access activity information, a temperature for the set of slices is determined by applying a predictive analysis technique. Based on the determination, relocation of data is effected in the storage system.

Abstract: A first storage system in one illustrative embodiment is configured to participate in a replication process with a second storage system. A first processing module of a distributed storage controller of the first storage system detects a replication failure condition for a given write request received from a host device, and provides a corresponding notification to a second processing module of the distributed storage controller. The second processing module, responsive to receipt of the notification, instructs the first processing module and a plurality of additional processing modules of a same type as the first processing module to suspend generation of replication acknowledgments for write requests received from the host device. Responsive to receipt of confirmation from the first and additional processing modules of their suspended generation of replication acknowledgements, the second processing module instructs the first and additional processing modules to terminate the replication process.

Abstract: A first storage system in one illustrative embodiment is configured to participate in a replication process with a second storage system. In conjunction with a synchronous replication mode of the replication process, a first processing module of a distributed storage controller of the first storage system is configured to write one or more data pages in the first storage system in accordance with a write request received from a host device, to send a corresponding replication write request to the second storage system, to determine whether or not the one or more data pages have been successfully replicated to the second storage system, and to update content-based signature mapping information of the one or more data pages responsive to receipt of an indication of successful replication. Responsive to a determination that the write request was received prior to initiation of the synchronous replication mode, an asynchronous-to-synchronous transition cycle scan operation is restarted.

Abstract: Described embodiments provide systems and processes for performing a data replication process in a storage system. A current asynchronous replication cycle is initiated at a time-based interval based upon a replication policy of the storage system to replicate data from at least one source device to at least one target device. For the current asynchronous replication cycle, it is determined whether data stored on portions of the source device has changed from a previous asynchronous replication cycle. A new replica of the source device is generated if data stored on the source device has changed from the previous asynchronous replication cycle. The new replica is transferred to the target device. The current asynchronous replication cycle is completed and the replication policy of the storage system is satisfied without generating the new replica if data stored on the source device has not changed from the previous asynchronous replication cycle.

Abstract: A system, computer program product, and computer-executable method of managing replication within a data storage system, the system, computer program product, and computer-executable method including receiving an error related to a replication session within the data storage system, analyzing the error, based on the analysis, determining whether to retry the replication session, upon a positive determination, calculating a first time interval for the replication session, and retrying the replication session upon completion of the first time interval.

Abstract: Described are techniques for processing data. Hash values for the data portions of a logical device are determined. Each data portion has a corresponding one of the hash values. It is determined whether a first of the hash values associated with a first of the data portions is equal to a hash value of an implied data value. If the first hash value is equal to the hash value of the implied data value, first processing is performed including determining whether the first data portion has a current data value equal to the implied data value, and responsive to determining that the first data portion has a current data value equal to the implied data value, performing second processing including updating first metadata for the first data portion to denote that the first data portion has the implied data value. The first data portion is not associated with allocated storage.

Abstract: An apparatus in one embodiment comprises at least one processing device comprising a processor coupled to a memory. The processing device is configured to capture metadata from a metadata area of a storage system for checkpointing, and to store the captured metadata as checkpointed metadata in a user data area of the storage system in association with mapping information relating portions of the checkpointed metadata to particular storage locations in the user data area. The processing device in some embodiments is implemented within the storage system, and may comprise a storage controller of the storage system. The mapping information illustratively comprises a plurality of page location arrays each having a plurality of entries specifying respective locations of checkpointed metadata pages in the user data area.

Abstract: A storage system comprising a processor in operable communication with a storage device is configured to have first, second, and third tables and first, second, and third respective metadata journals storing time-based information associated, respectively, with the first, second, and third tables. The first table maps logical addresses associated with LUNs associated with the storage device to respective hash digests computed based on data residing at respective logical addresses. The second table maps a range of hash digests to respective associated physical locations on the storage device. The third table maps disk block allocation on the storage device. An online system checkpoint is created, comprising information relating to the state of the storage system at a point in time, where the first, second, and third, metadata journals are destaged in order so as to destage information stored in the respective journal up to the point in time.

Abstract: An apparatus in one embodiment comprises a storage system having a plurality of storage devices and an associated storage controller. The storage devices are configured to provide a metadata area and a user data area, the user data area being separated into pages. The storage controller is configured to initiate generation of one or more checkpoints in the storage system. In conjunction with the generation of a given one of the one or more checkpoints in the storage system, the storage controller causes checkpointed metadata from the metadata area to be stored in the user data area. The storage controller further stores mapping information relating portions of the checkpointed metadata to respective pages of the user data area that store those portions of the checkpointed metadata. The mapping information illustratively comprises page location arrays and array location arrays, and in some embodiments further comprises one or more higher-level location arrays.

Abstract: A computer-implemented method is provided for a storage system comprising a processor in operable communication with a storage device that is configured into a plurality of respective regions of storage space. A first defragmentation process is performed on at least a first region of the plurality of respective regions of storage space to free a first portion of storage space in the a respective first region, where the freed first portion is reserved for user data and metadata associated with I/O requests to the storage system that are generated during a first operation running on the storage system. The storage system is configured to ensure that, during the first operation, user data and metadata are routed towards the first freed portion and kept separate from a set of system checkpoint information, associated with a first state of the storage system, stored in a protected portion of storage space.

Abstract: Described embodiments may provide systems and processes for migrating a replica hierarchy from at least one source device to at least one target device in a storage system. A configuration of the replica hierarchy is migrated, one or more internal nodes of the replica hierarchy are migrated, and one or more leaf nodes of the replica hierarchy are migrated. A cutover operation is performed by deactivating the at least one source device associated with the included replica hierarchy.

Abstract: A method is used in managing data placement in storage systems. A portion of an allocated storage space is identified in a data storage system for managing data placement. The allocated storage space includes first and second set of slices. The first set of slices associated with the portion of the allocated storage space in the data storage system is identified. Data of the first set of slices is transferred to the second set of slices of the allocated storage space in the data storage system. The first set of slice is removed from the allocated storage space in the data storage system.

Abstract: A technique for replicating a file from a source data storage system (source) to a destination data storage system (destination) includes receiving, by the destination from the source, (i) file data for multiple logical extents of the file and (ii) respective tiering metadata for those logical extents. The destination selects, based on the tiering metadata, one or more storage tiers available on the destination. The destination updates a local replica of the file by placing the logical extents on the selected tier or tiers.

Abstract: A method is used in managing data relocation in storage systems. Metadata of a slice of a storage tier in a data storage system is evaluated for migrating the slice from the storage tier to another storage tier. The data storage system includes a first storage tier and a second storage tier configured such that performance characteristics associated with the first storage tier is superior to the second storage tier. Based on the evaluation, relocation of the slice of the storage tier is effected. The metadata of the slice indicates whether the slice includes user data.

Abstract: A method is used in managing data in a data storage system. A tiered storage pool is identified wherein the storage pool includes multiple tiers having multiple storage units. A wear indicator for each of the multiple storage units is monitored. A first storage unit having a wear indicator greater than a second storage unit is identified. High activity data on the first storage unit is also identified. The identified high activity data is migrated from the first storage unit to the second storage unit.

Abstract: A method is used in managing data relocation in storage systems. A request is received to write to a slice of storage tier in a data storage system where the slice is being relocated. The relocation of the slice includes copying data of the slice to another slice in the data storage system. Location within the slice at which the request to write to the slice has been received is determined. Based on the determination, relocation of the slice of the storage tier is effected.

Abstract: Example embodiments of the present invention relate to methods, systems, and computer program products for determining replicas for removal from a plurality of replicas as defined in a data retention policy. The method includes performing asynchronous replication from a source to a target according to time-based replication cycles. A retention policy then may be identified defining a number of asynchronous replication replicas to retain and a plurality of associated periods which then may be retained according to the policy.

Abstract: Techniques are described for storing data. A command is issued from a client to a data storage system. The data storage system includes a plurality of storage tiers comprising a first storage tier of physical storage devices and a second storage tier of physical storage devices, wherein data stored on any physical storage device of the first storage tier is stored in an encrypted form and data stored on any physical storage device of the second storage tier is not stored in an encrypted form. The command includes a hint indicating whether data stored at a first logical address range of a first logical device is stored in an encrypted form. The command is received at the data storage system. First data written to the first logical device at the first logical address range is stored on one or more physical storage devices of any of said first storage tier and said second storage tier in accordance with the hint.

Abstract: A technique manages host data in a data storage array. The technique involves placing, in response to host input/output (I/O) requests from a set of host devices, host data in a container file system which is stored in a slice pool of storage slices (e.g., storage space of a standard size such as 256 MB) formed by multiple storage tiers of the data storage array. Each storage tier provides storage access at a different storage access speed. The technique further involves assigning classifications to storage slices of the slice pool which store the container file system, each classification being assigned based on storage slice access history resulting from the host I/O requests. The technique further involves relocating portions of the container file system among the multiple storage tiers according to the classifications assigned to the storage slices of the slice pool.

Abstract: A method is used in managing data relocation in storage systems. Data relocation elapsed time is determined in a storage system. The data relocation elapsed time indicates time taken to relocate data of storage objects in the storage system. Based on the determination, relocation of data is effected in the storage system. Effecting relocation of the data includes adjusting relocation of the data of a set of storage objects. The number of storage objects in the set of storage objects is changed based on the data relocation elapsed time.