Abstract: A method, computer program product, and computing system for receiving, at a cache memory system, a write request for writing data to a storage system. A data reduction rate may be predicted for the write request. One or more portions of memory within the storage system may be allocated based upon, at least in part, the predicted data reduction rate for the write request. The write request may be flushed from the cache memory system to the allocated one or more portions of memory within the storage system.

Abstract: For each of multiple storage volumes of a distributed storage system, it is determined whether the storage volume has a relatively high potential deduplicability or a relatively low potential deduplicability. Responsive to determining that the storage volume has the relatively high potential deduplicability, a first write flow is executed for each of a plurality of write requests directed to the storage volume, the first write flow utilizing content-based signatures of respective data pages of the storage volume to store the data pages in storage devices of the distributed storage system. Responsive to determining that the storage volume has the relatively low potential deduplicability, a second write flow is executed for each of a plurality of write requests directed to the storage volume, the second write flow utilizing non-content-based signatures of respective data pages of the storage volume to store the data pages in storage devices of the distributed storage system.

Abstract: An aspect of performing rollback of a snapshot between source and target storage systems in an asynchronous replication session in which Sr? represents a remote snapshot subject to the rollback includes suspending host input/output operations to a current source volume (Vs), determining whether a snapshot (Sr) matching the snapshot Sr? is present in the source system and, upon determining the snapshot Sr is not present in the source storage system, searching a snapshot pair (Sk, Sk?) that is closest to the remote snapshot Sr?. An aspect also includes upon determining the pair Sk, Sk? is present in existing snapsets, performing a local rollback of the Vs to Sk, and performing remote rollback including applying a difference between Sk? and Sr? to the Vs via one of a snapshot differential bitmap from the target storage system between Sk? and Sr? for the Vs, and an internal reverse direction asynchronous replication cycle.

Abstract: Techniques are used for enabling deduplication for asynchronous replication in a storage system. The techniques may be used to provide, among other things, retrieving, on a source system, a virtual index key corresponding to a logical address, and determining whether a deduplication index table for a target system includes an entry with the same virtual index key.

Abstract: For each of a plurality of commit operations to be executed for respective given code portions of a set of software code under development, at least one processing device performs a relevance analysis to identify one or more other code portions of the set of software code that each exhibits at least a threshold level of relevance to the given code portion, determines one or more code reviewers for the given code portion based at least in part on the one or more other code portions identified by the relevance analysis, assigns code review responsibilities for the given code portion to the one or more determined code reviewers, notifies the one or more determined code reviewers of the assigned code review responsibilities, and responsive to successful completion of code review by the one or more determined code reviewers, executes the commit operation for the given code portion.

Abstract: A technique for validating metadata includes creating log entries for virtualization structures pointed to by mapping pointers in a mapping tree and processing the log entries in multiple passes. A current pass validates a current level of redirection and creates new log entries to be processed during a next pass. The new log entries represent a next level of redirection, and as many next passes are processed in sequence as there are next levels of redirection.

Abstract: An aspect of performing rollback of a snapshot between a source storage system and a target storage system in a synchronous replication session includes reassigning a current replication source volume to a rollback source snapshot. The rollback source snapshot is generated for a consistency group that includes a plurality of volumes. An aspect also includes performing, for one or more snapshot trees maintained for the consistency group, a differential scan between a child of the rollback source snapshot and the current replication source volume, and calculating, from results of the differential scan, a dirty tree differential. For each difference identified in the dirty tree differential, an aspect further includes calculating a corresponding volume offset, and initiating a copy command for the current replication source volume and the rollback source snapshot. The copy command is translated to a remote metadata copy request in synchronous replication data transfer.

Abstract: For each of a plurality of commit operations to be executed for respective given code portions of a set of software code under development, at least one processing device performs a relevance analysis to identify one or more other code portions of the set of software code that each exhibits at least a threshold level of relevance to the given code portion, determines one or more code reviewers for the given code portion based at least in part on the one or more other code portions identified by the relevance analysis, assigns code review responsibilities for the given code portion to the one or more determined code reviewers, notifies the one or more determined code reviewers of the assigned code review responsibilities, and responsive to successful completion of code review by the one or more determined code reviewers, executes the commit operation for the given code portion.

Abstract: A method, computer program product, and computer system for receiving, at a computing device, a write request from a host, wherein a first portion of a process may receive the write request. A callback and context may be set in the write request by the first portion of the process. The write request may be passed to a second portion of the process. The first process may be provided with the context. The first process may use the context to replicate the write request data to a destination.

Abstract: An apparatus in one embodiment includes at least one processing device comprising a processor coupled to a memory, with the at least one processing device being configured to maintain a replication journal for recording replication write requests in a storage system, to detect a failure impacting the replication journal, and to initiate recovery of the replication journal responsive to the detected failure. In conjunction with the recovery of the replication journal, the at least one processing device is further configured to maintain a lock contention table that characterizes lock contentions between address lock ranges required for the recovery of the replication journal and address lock ranges required by other write requests in the storage system, and to utilize the lock contention table to resolve one or more potential deadlocks that would otherwise prevent completion of the recovery of the replication journal. Other embodiments include methods and computer program products.

Abstract: An apparatus includes a processing device comprising a processor coupled to a memory, with the processing device being configured, in conjunction with synchronous replication of at least one logical storage volume between first and second storage systems, to acquire an address lock for a set of pages of the logical storage volume starting from a particular page of the logical storage volume, to determine content-based signatures for respective pages of the set of pages, to compute an additional signature as a function of the content-based signatures, and to send the additional signature and a pointer to the particular page from the first storage system to the second storage system, so as to permit the second storage system to verify consistency of the set of pages in the second storage system relative to the set of pages in the first storage system. Such operations are repeated for other sets of pages.

Abstract: For each of multiple storage volumes of a distributed storage system, it is determined whether the storage volume has a relatively high potential deduplicability or a relatively low potential deduplicability. Responsive to determining that the storage volume has the relatively high potential deduplicability, a first write flow is executed for each of a plurality of write requests directed to the storage volume, the first write flow utilizing content-based signatures of respective data pages of the storage volume to store the data pages in storage devices of the distributed storage system. Responsive to determining that the storage volume has the relatively low potential deduplicability, a second write flow is executed for each of a plurality of write requests directed to the storage volume, the second write flow utilizing non-content-based signatures of respective data pages of the storage volume to store the data pages in storage devices of the distributed storage system.

Abstract: Techniques are used for enabling deduplication for asynchronous replication in a storage system. The techniques may be used to provide, among other things, retrieving, on a source system, a virtual index key corresponding to a logical address, and determining whether a deduplication index table for a target system includes an entry with the same virtual index key.

Abstract: A first storage system in one illustrative embodiment is configured to participate in a replication process with a second storage system. The first storage system detects a replication failure condition or other condition requiring termination of a synchronous replication mode of the replication process, and responsive to the detected condition, captures a snapshot of source data that is subject to replication from the first storage system to the second storage system as part of the replication process. The first storage system terminates the synchronous replication mode of the replication process, initiates an asynchronous replication mode of the replication process, executes an asynchronous-to-synchronous transition cycle scan operation for the replication process utilizing the captured snapshot, and resumes the synchronous replication mode of the replication process responsive to successful completion of the asynchronous-to-synchronous transition cycle scan operation.

Abstract: 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.

Abstract: A method is provided, comprising: receiving, at a first storage array, a first request to perform an atomic write operation at a specified address in a volume; placing a read-write lock on a first instance of the volume, and executing the atomic write operation on the first instance of the volume; transmitting, to a second storage array, a second request to perform the atomic write operation on a second instance of the volume; and detecting whether an error condition is present that is associated with the second request; when the error condition is present, comparing a first data item that is stored at the specified address in the first instance of the volume with a second data item that is stored at the specified address in the second instance of the volume, and, when the first data item matches the second data item, transmitting an acknowledgment.

Abstract: A method is provided, comprising: receiving, from a host device, a request to create a token that represents one or more data items that are stored in a first volume, the first volume being stored in a source system; estimating an I/O latency limit for the first volume; estimating a token creation time for the token; comparing the token creation time to the I/O latency limit; when the token creation time matches the I/O latency limit: creating the token, creating a snapshot pair, mapping the token to the snapshot pair, and returning the token to the host device; when the token creation time does not match the I/O latency limit: creating the token, creating a first snapshot of the first volume at the source system, mapping the first snapshot to the token, and returning the token to the host device.

Abstract: A method for use in a storage system disclosed, comprising: transitioning the storage system into a first state, the first state including a state in which a source system performs synchronous replication to a target system; detecting a first event while the source system is in the first state; in response to the first event, transitioning the storage system from the first state into a second state, the second state being a state in which the source system performs asynchronous replication; detecting a second event while the storage system is in the second state, transitioning the source system from the second state into a third state, the third state including a state in which the source system performs both synchronous replication and asynchronous replication.

Abstract: A method is provided, comprising: receiving, at a first storage array, a first request to perform an atomic write operation at a specified address in a volume; placing a read-write lock on a first instance of the volume, and executing the atomic write operation on the first instance of the volume; transmitting, to a second storage array, a second request to perform the atomic write operation on a second instance of the volume; and detecting whether an error condition is present that is associated with the second request; when the error condition is present, comparing a first data item that is stored at the specified address in the first instance of the volume with a second data item that is stored at the specified address in the second instance of the volume, and, when the first data item matches the second data item, transmitting an acknowledgment.

Abstract: An apparatus in one embodiment comprises at least one processing device comprising a processor coupled to a memory. The at least one processing device is configured to identify a storage volume to be added to a first consistency group of a first synchronous replication session between a first storage system and a second storage system in an active-active configuration, to create a second synchronous replication session for the added storage volume between the first storage system and the second storage system, and to merge the first and second synchronous replication sessions responsive to one or more designated criteria. The second synchronous replication session is illustratively configured to be fully independent of the first synchronous replication session.