Abstract: A method, computer program product, and computer system for receiving, by a computing device, an IO request. It may be determined that data of the IO request includes an indication of an attribute. A prefix descriptor may be constructed for the data in a self-descriptive page buffer based upon, at least in part, determining that the data of the IO request includes the indication of the attribute. An appropriate Application Programming Interface (API) may be called to process the IO request based upon, at least in part, the prefix descriptor.

Abstract: An apparatus comprises a storage system having storage devices and an associated storage controller. In conjunction with initiation of a checkpoint, the storage controller sets a checkpoint started flag for the checkpoint, marks user data pages and metadata pages for write operations already entered in a write journal of the storage system as of the setting of the checkpoint started flag as checkpoint pages, and marks user data pages and metadata pages for new write operations entered in the write journal after the setting of the checkpoint started flag as non-checkpoint pages by altering information used to generate signatures for respective ones of the metadata pages. Metadata pages characterizing the same user data pages subject to write operations at different times thereby have different signatures depending on whether or not the checkpoint started flag was set when its corresponding write operation was entered in the write journal.

Abstract: An apparatus includes at least one processing device comprising a processor coupled to a memory, with the processing device being configured to maintain a synchronous replication input-output (IO) request list having a plurality of entries corresponding to respective synchronous replication IO requests, a given such entry identifying at least a sender component and one or more associated component resources to be released responsive to a failure of the sender component. The processing device is further configured to detect a failure of a particular one of a plurality of sender components, to access the synchronous replication IO request list to determine one or more associated component resources to be released, to release the one or more associated component resources, and to update the synchronous replication IO request list by marking the one or more associated component resources as released. Other embodiments include methods and computer program products.

Abstract: Techniques for providing a direct IO path to compressed data on storage media of a storage system. The techniques include triggering a transaction cache to perform a flush operation for updating mapping metadata for a storage object containing the compressed data. Having updated the mapping metadata for the storage object, the techniques further include issuing, by a copier module, an IO read request for the compressed data of the storage object to a namespace layer, which issues the IO read request to a mapping layer. The techniques further include forwarding the IO read request to a logical layer of the mapping layer, bypassing the transaction cache. The techniques further include reading, by the logical layer, the compressed data of the storage object from the storage media, and providing, via the mapping layer and the namespace layer, the compressed data to the copier module for transfer to a destination storage system.

Abstract: A technique versions a configuration of data storage equipment. The technique involves receiving, while the data storage equipment operates in accordance with a first version of the configuration of the data storage equipment, a configuration change command to change the configuration of the data storage equipment. The technique further involves changing the first version of the configuration of the data storage equipment to a second version of the configuration of the data storage equipment in response to the configuration change command. The technique further involves, while the data storage equipment operates in accordance with the second version of the configuration of the data storage equipment, concurrently maintaining access to the first version of the configuration of the data storage equipment and the second version of the configuration of the data storage equipment.

Abstract: A method is disclosed comprising: instantiating a first plurality of type-1 network sockets on a source computing system, each of the type-1 network sockets having a first queue depth; instantiating a second plurality of type-2 network sockets on the source computing system, each of the type-2 network sockets having a second queue depth that is greater than the first queue depth; transitioning the source computing system into a first state, the first state being one in which data replication messages are transmitted by the source computing system to a target computing system by using both the type-1 and type-2 network sockets; transitioning the source computing system from the first state.

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 storage system is configured to comprise a processor in operable communication with a storage device and a metadata journal comprising metadata configured to store information associated with a change to be made to information stored on the storage device. While the storage system is booted up and responsive to I/O requests from a host, a scan is performed of a first portion of metadata that is loaded into storage system memory during the bootup, to check for existence of a metadata inconsistency condition comprising at least one of: (a) dirty tree (DT) entries in the metadata associated with an invalid logical unit (LU) index; (b) hash tree (HT) entries in the metadata which do not have corresponding DT bits; and (c) DT bits set without having a corresponding HT entry. Based on the results of the first scan, a determination is made about whether a first metadata inconsistency condition exists.

Abstract: A storage system in one embodiment comprises a plurality of storage devices and a storage controller. The storage system is configured to implement a loopback replication process in which one or more source storage objects are replicated to one or more corresponding target storage objects within the storage system. The storage system is further configured to divide a storage space provided by at least portions of the storage devices of the storage system into slices, to subdivide the slices into source slices and target slices, and to replicate a source storage object associated with at least one of the source slices to a target storage object associated with at least one of the target slices. The source storage object may be associated with at least one of the source slices by, for example, storing the source storage object across portions of the storage devices in designated ones of the source slices.

Abstract: An apparatus in one embodiment comprises a host device that includes at least one processor and an associated memory. The host device is configured to implement a plurality of processes each configured to access a shared region of the memory. The host device is further configured to establish a multi-process control group for the shared region, to maintain state information for the multi-process control group, and to track usage of the shared region by the processes based at least in part on the state information. At least a subset of the processes may comprise respective containers implemented utilizing operating system level virtualization of the processor of the host device. The multi-process control group established for the shared region illustratively comprises a coarse-grained control group having a granularity greater than a single page of the shared region.

Abstract: A method is disclosed comprising: generating a plurality of snapshots, each of the snapshots representing a state of one or more storage objects in a storage system; generating a plurality of access pattern records (APRs) for the storage objects, each APR being associated with a different respective one of the plurality of snapshots, each APR indicating a characteristic of workload of the storage system in a period preceding the generation of the APR's associated snapshot; detecting a workload trend for the storage objects, the workload trend being detected by using a workload prediction model that is trained based on the plurality of APRs; and configuring the storage system based on the workload trend, the configuring including allocating additional resources for servicing access requests to the storage objects when the workload trend is a rising workload trend.

Abstract: A first storage system in one illustrative embodiment is configured to participate in a replication process with a second storage system. Each of a plurality of storage nodes of the first storage system comprises a plurality of storage devices and a set of processing modules configured to communicate with corresponding sets of processing modules on other ones of the storage nodes. In conjunction with the replication process, a first one of the processing modules is configured to generate a request message for transmission to a second one of the processing modules requesting that the second processing module transfer designated replication data to the second storage system. The request message comprises a unique message identifier that the second processing module incorporates into a subsequent response message transmitted back to the first processing module to indicate a result of the requested transfer of the designated replication data to the second storage system.

Abstract: In one aspect, minimization of recovery time after a high availability (HA) event in a storage system is provided. An aspect includes creating, during an active replication session, mini replication session MOM objects from replication session-related configuration information of the active replication session, and creating mini volume objects for volumes of the active replication session, Upon determining an occurrence of the HA corresponding to the data module, an aspect includes reconfiguring the mini replication session MOM objects and the mini volume objects prior to activation of the data module and prior to enabling input/output (TO) servicing by the data module. An aspect further includes performing non-replication IO-related configuration for the data module and, upon completion of the non-replication IO-related configuration, enabling the IO servicing by the data module.

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 method is used in managing asynchronous replication. The method receives a multi-page replication request in conjunction with the replication process, where the first storage system comprises a plurality of storage devices and the second storage system comprises a plurality of storage devices. The method determines at least one replication condition meets a threshold. In response, the method optimizes the multi-page replication request to optimize the replication process.

Abstract: An aspect includes generating a checkpoint for a storage system containing an image for a point in time. An aspect also includes storing, in a reserved area, volume configuration data corresponding to volumes for the point in time, layers of metadata and physical data for the point in time. An aspect further includes creating consistent snapshots for the volumes, destaging a control module journal and persisting a hash tree and dirty tree metadata, destaging a code cache, dumping hash metadata and physical layout metadata to a separate location in the storage and enabling new metadata updates to a default location. An aspect also includes redirecting new data and metadata IOS to stripes reserved during preparation of the separate location relating to the checkpoint and protecting checkpointed data and metadata, and generating a consistent checkpoint copy of a management module repository in the reserved area of storage.

Abstract: In one aspect, extent lock resolution for storage devices includes designating one of the storage devices as a lock winner, which takes priority over another storage device over a lock. An aspect also includes receiving a replication request issued, by a host during active/active replication, determining an extent of pages to be modified by the request, locking the extent in local storage device, and executing the request at the local device. An aspect also includes sending a write request to a remote device. If the remote device is the designated lock winner, and an attempt to lock the extent is unsuccessful, the remote device waits for the lock to become available. If the remote device is not the designated lock winner, and an attempt to lock the extent is unsuccessful, the remote device rejects the write request and sends a request to the local device to resend the write request.

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 of one or more snapshot trees maintained for the consistency group, a determination is made as to whether or not a first node corresponding to the previous snapshot set is an ancestor of a second node corresponding to the current snapshot set, and a manner in which an instance of the differential scan is performed for the snapshot tree is altered responsive to a result of the determination.

Abstract: A storage system in one embodiment is configured to participate as a source storage system in a synchronous replication process with a target storage system. In verifying synchronously replicated data, the source storage system generates a current snapshot for one or more storage volumes subject to synchronous replication to the target storage system, identifies a plurality of pages of the current snapshot that have changed since generation of a previous snapshot for the one or more storage volumes, obtains content-based signatures for respective ones of the changed pages, assigns the changed pages to a page group, generates a group signature for the page group based at least in part on the content-based signatures of the pages of the page group, and sends the group signature to the target storage system. The group signature is configured to allow the target storage system to determine if the page group contains at least one page that is inconsistent between the source and target storage systems.

Abstract: An apparatus is configured to initiate a first replication session to replicate data of a first consistency group in a first storage system to a second consistency group in a second storage system, to create an additional consistency group linked to the second consistency group in the second storage system, and to initiate a second replication session to replicate data of the additional consistency group to another consistency group in a third storage system. The additional consistency group linked to the second consistency group in some embodiments is periodically updated against the second consistency group. For example, in one or more embodiments the second consistency group is updated based at least in part on an active snapshot set of the first replication session, and the additional consistency group is updated based at least in part on the second consistency group.