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 detect an error relating to storage of a given data page in a first storage system, and to send a message to at least one additional storage system, the message containing a hash digest of the given data page. The processing device is further configured to receive from the additional storage system responsive to the message a recovery data page identified by the additional storage system as having the same hash digest as the given data page. The recovery data page received from the additional storage system is verified by computing a hash digest of the recovery data page and comparing the computed hash digest to the hash digest of the given data page. Separate instances of the message containing the hash digest of the given data page may be sent to each of a plurality of additional storage systems.

Abstract: A first storage system is arranged in an active-active configuration with a second storage system. The first storage system receives from a host device a first command of a multiple-command token-based data transfer, the first command specifying a source extent of a storage volume. The first storage system suspends all writes to the storage volume in the first storage system; directs the second storage system to suspend all writes to the storage volume in the second storage system; takes a snapshot of the storage volume in the first storage system; directs the second storage system to take a snapshot of the storage volume in the second storage system; associates a token with the source extent of the storage volume and the snapshot in the first storage system; sends the token to the second storage system; and directs the second storage system to associate the token with the source extent of the storage volume and the snapshot in the second storage system.

Abstract: 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.

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 schedule generation of a point-in-time replica of one or more logical storage volumes of a storage system, to generate a test metadata file for a data integrity test to be performed utilizing the point-in-time replica, and to store the test metadata file in at least one of the one or more logical storage volumes for which the point-in-time replica is to be generated. The point-in-time replica may comprise a snapshot of a replication consistency group comprising the one or more logical storage volumes of the storage system. Scheduling the generation of the point-in-time replica of the one or more logical storage volumes of the storage system illustratively comprises initiating an asynchronous replication process for a replication consistency group comprising the one or more logical storage volumes of the storage system.

Abstract: An apparatus is configured to generate a current snapshot set for a consistency group comprising a plurality of storage volumes subject to replication from a source storage system to a target storage system, and to schedule a differential scan of the current snapshot set relative to a previous snapshot set generated for the consistency group. For each snapshot tree of a first group of one or more snapshot trees of the current snapshot set, a non-root node is identified as a start node. For each snapshot tree of a second group of one or more other snapshot trees of the current snapshot set, a root node of that snapshot tree is identified as a start node. Differential scan is performed for each snapshot tree of the first group, and full scan is performed for each snapshot tree of the second group.

Abstract: An aspect includes determining a host write rate based on a number of chunks written to a storage volume during a first replication cycle and determining a target rate based on an estimated number of chunks written during a second replication cycle. The target rate is determined by dividing the number of chunks written during the second replication cycle by a recovery point objective (RPO) period. An aspect also includes transmitting chunks written during the second replication cycle at the target rate.

Abstract: Described embodiments provide systems and methods for performing hash-based data replication in a storage system. The hash-based data replication replicates selected data from a source device to a target device of the storage system. One or more operating conditions of the storage system are determined. Based upon the determined operating conditions, one or more configuration settings of data replication operations are set. The data replication operation is initiated for the selected data, and sends, based upon the one or more configuration settings, at least one of (i) a hash value associated with the selected data to the one or more target devices, and (ii) the selected data to the one or more target devices.

Abstract: In one aspect, performance optimization for data persistency in asynchronous replication setups includes creating at a source site of a data replication system, a snapshot (snapshot N) of input/output (IO) requests as part of a replication cycle, computing a delta of snapshot N and a previously created snapshot (snapshot N?1), and transmitting the delta to a target site of the data replication storage system. An aspect further includes storing, at the target site, snapshot N?1 during transmission of the delta, and caching the delta to a non-persistent storage device. Upon determining an occurrence of a loss event at the target site, a further aspect includes transmitting, by the target site, a request to retransmit the delta, retransmitting, by the source site, the delta to the target site, caching the delta to the non-persistent storage device until successful transmission of the delta, and committing the transmitted delta to permanent storage.

Abstract: A storage system in one embodiment comprises a plurality of storage devices and a storage controller. The storage system is configured to participate as a target storage system in a replication process with a source storage system. In conjunction with the replication process, the target storage system is configured to receive from the source storage system replication data for at least one storage volume subject to replication from the source storage system to the target storage system, to generate a first snapshot for the storage volume, to monitor additional replication data received from the source storage system for the storage volume after generation of the first snapshot, and responsive to the monitored additional replication data satisfying one or more specified conditions, to perform at least one of the following operations: (i) generating a subsequent snapshot for the storage volume; and (ii) marking the first snapshot with a priority indicator.

Abstract: A storage system in one embodiment comprises a plurality of storage devices and a storage controller. The storage controller is configured to generate a plurality of snapshots of a storage volume of the storage system at respective different points in time, to monitor a differential between a given one of the snapshots and the storage volume, and to generate an alert indicative of at least a potential ransomware attack on the storage system based at least in part on the monitored differential satisfying one or more specified conditions. The one or more specified conditions illustratively comprise a specified minimum amount of change in the storage volume relative to the given snapshot of the storage volume. Compressibility of the storage volume is also taken into account in generating the alert in some embodiments. The storage controller illustratively initiates restoration of the storage volume utilizing a selected snapshot responsive to confirmation of an actual attack.

Abstract: A content addressable storage system in one embodiment comprises a plurality of storage devices and a storage controller. The content addressable storage system is configured to receive from another storage system a plurality of snapshots for at least one storage volume designated for backup from the other storage system to the content addressable storage system. For each of a plurality of pages of a given one of the snapshots, the content addressable storage system generates a content-based signature for the page, compares the content-based signature for the page to a previous content-based signature generated for a corresponding page having the same address in a previous one of the snapshots, and stores the page of the given snapshot in one or more of the storage devices of the content addressable storage system responsive to an absence of a match between the compared content-based signatures. The content-based signatures illustratively comprise respective hash handles.

Abstract: A storage system in one embodiment comprises a plurality of storage devices and a storage controller. The storage controller is configured to monitor a differential between a storage volume of the storage system and a previous snapshot generated for that storage volume, and responsive to the monitored differential satisfying one or more specified conditions, to generate a subsequent snapshot for the storage volume. For example, monitoring the differential between the storage volume of the storage system and the previous snapshot generated for that storage volume illustratively comprises maintaining a counter indicative of an amount of data in the storage volume that has been written since generation of the previous snapshot. In such an arrangement, generating the subsequent snapshot for the storage volume responsive to the monitored differential satisfying one or more specified conditions illustratively comprises generating the subsequent snapshot responsive to the counter exceeding a specified threshold.

Abstract: A System, computer program product, and computer-executable method of transitioning replication on a data storage system including a production site and a replication site from asynchronous replication to synchronous replication, the System, computer program product, and computer-executable method including receiving a request to transition from asynchronous replication to synchronous replication and changing the data storage system to a transition mode, wherein the data storage system transitions the data storage system from using asynchronous replication to synchronous replication.

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: A storage system in one embodiment comprises a plurality of storage devices and a storage controller. The storage system is configured by the storage controller to receive a plurality of data records in a count-key-data format, to separate count and key portions of the data records from remaining portions of the data records, to store the count and key portions of the data records in at least one designated page of a set of pages of a logical storage volume of the storage system, and to store the remaining portions of the data records in one or more other pages of the set of pages of the logical storage volume of the storage system. The designated page of the set of pages of the logical storage volume may comprise a first page of the set of pages, and the one or more other pages of the set of pages may comprise respective ones of a sequence of consecutive pages following the first page.

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 schedule generation of a point-in-time replica of one or more logical storage volumes of a storage system, to generate a test metadata file for a data integrity test to be performed utilizing the point-in-time replica, and to store the test metadata file in at least one of the one or more logical storage volumes for which the point-in-time replica is to be generated. The point-in-time replica may comprise a snapshot of a replication consistency group comprising the one or more logical storage volumes of the storage system. Scheduling the generation of the point-in-time replica of the one or more logical storage volumes of the storage system illustratively comprises initiating an asynchronous replication process for a replication consistency group comprising the one or more logical storage volumes of the storage system.

Abstract: A storage system in one embodiment comprises multiple storage nodes each comprising at least one storage device. Each of the storage nodes further comprises a set of processing modules configured to communicate over one or more networks with corresponding sets of processing modules on other ones of the storage nodes. The sets of processing modules of the storage nodes each comprise at least one control module. The storage system is configured to assign portions of a logical address space of the storage system to respective ones of the control modules, to receive a plurality of tracks of data records in a count-key-data format, and to store the tracks in respective ones of the portions of the logical address space assigned to respective ones of the control modules. Each of the tracks is stored in its entirety in the portion of the logical address space assigned to a corresponding one of the control modules.

Abstract: An apparatus in one embodiment comprises at least one processing device comprising a processor coupled to a memory. The processing device is configured, in a first phase of a given write operation of a data integrity test process, to associate with each of a plurality of pages of the given write operation at least one additional field having a designated signature, and in a second phase of the given write operation, to modify the signature of the additional field for each of the pages. The processing device is further configured, in a given read operation of the data integrity test process, to determine integrity of each of at least a subset of the pages based at least in part on the signature of its associated additional field. The data integrity test process may be configured to confirm consistency of the pages written by the given write operation relative to a corresponding point-in-time replica.

Abstract: A computer program product, system, and method for determining a number of chunks written to a storage volume during a first replication cycle; determining a host write rate based on the number of chunks written to the storage volume during the first replication cycle; estimating a number of chunks written during a second replication cycle; determining a target rate based on the estimated number of chunks written during the second replication cycle; and transmitting chunks written during the second replication cycle at the target rate.

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 identify a dataset to be scanned to generate a deduplication estimate for that dataset, to designate a subset inclusion characteristic to be utilized in the scan, and for each of a plurality of pages of the dataset, to scan the page, where scanning the page includes computing a polynomial-based signature for the page, determining whether or not the polynomial-based signature satisfies the designated subset inclusion characteristic, and responsive to the polynomial-based signature satisfying the designated subset inclusion characteristic, computing a content-based signature for the page and updating a corresponding entry of a deduplication estimate table for the dataset based at least in part on the content-based signature.