Techniques for determining replication modes may include: issuing, while unsolicited data transfer mode is enabled for a first link, first write operations over the first link; issuing, while unsolicited data transfer mode is disabled for the first link, second write operations over the first link; determining a first performance metric for the first link in accordance with the first write operations; determining a second performance metric for the first link in accordance with the second write operations; and determining, in accordance with the first and second performance metrics whether to enable or disable unsolicited data transfer mode for the first link for a first time period. The first and second performance metrics may be response times. Unsolicited data transfer mode, when enabled, allows write data payload to be sent to a target without receiving an acknowledgement regarding receipt of a write command block for the write operation from the target.

In example implementations, unreferenced memory addresses in a segment of a storage volume may be identified. Access to the segment of the storage volume may be controlled by one of a plurality of storage volume controllers (SVCs). The plurality of SVCs may control access to respective segments of the storage volume. Indicators of the identified unreferenced memory addresses may be stored in a volatile memory in the one of the plurality of SVCs. In response to an input/output (I/O) command from a host, data may be written to one of the identified unreferenced memory addresses corresponding to one of the indicators stored in the volatile memory. After the data has been written, the one of the indicators may be deleted from the volatile memory. The one of the identified unreferenced memory addresses may not have been made available to other SVCs after being identified.

Systems, methods, and computer program products for mirroring dual writeable storage arrays are provided. Various embodiments provide configurations including two or more mirrored storage arrays that are each capable of being written to by different hosts. When commands to write data to corresponding mirrored data blocks within the respective storage arrays are received from different hosts at substantially the same time, write priority for writing data to the mirrored data blocks is given to one of the storage arrays based on a predetermined criterion or multiple predetermined criteria.

A first non-volatile dual in-line memory module (NVDIMM) of a first server and a second NVDIMM of a second server are armed during initial program load in a dual-server based storage system to configure the first NVDIMM and the second NVDIMM to retain data on power loss. Prior to initiating a safe data commit scan to destage modified data from the first server to a secondary storage, a determination is made as to whether the first NVDIMM is armed. In response to determining that the first NVDIMM is not armed, a failover is initiated to the second server.

A clustered pair of data storage nodes employs a time-to-live (TTL) mechanism by which a preferred node communicates permission for continued operation to a non-preferred node. During non-errored TTL operation, host I/O requests to a data storage object are serviced, with write-type requests being replicated to the other node. Upon a failure as indicated by errored TTL operation or failure of replication, a polarization operation selects a surviving node to transition to single-node access to the data storage object. The polarization process includes: (1) each node contacting a witness node to request survivor status, (2) the witness node granting survivor status to the first node requesting it and denying survivor status to a later-requesting node, (3) at the node granted survivor status, continuing to service the host I/O requests without replication, and (4) at the other node based on being denied survivor status, discontinuing servicing of the host I/O requests.

Certain embodiments described herein relate to an improved information management system that can perform platform-agnostic containerized application data protection. In one embodiment, the information management system receives a user's credentials to a container orchestrator along with an indication of whether or not to deploy a backup pod. Using the user credentials, the information management system accesses the container orchestrator, and if the user has requested deployment of a backup pod on the user's cluster, the information management system may do so using a backup pod specification and allow the backup pod to perform data protection operations, using a platform-agnostic interface (e.g., container storage interface), for application data accessible by the user applications on the user's pod on the user's cluster. Alternatively, if the user has not requested deployment of a backup pod, the information management system may perform data protection operations using provider-specific interface.

In a data backup method performed in a storage system having multiple storage devices, a first storage device having a firs LUN queries data consistency points from a second storage device that has a second LUN which has an active-active relationship with the first LUN. The second storage device obtains the data consistency points based on the IO data status record of the first LUN and an IO data status record of the second LUN stored in the second storage device, and provides the data consistency points to the first storage device. The first storage device then creates a snapshot for the first LUN based on the data consistency points, provides differential data between the current snapshot and a previous snapshot, and stores the differential data in the backup storage device.

Certain embodiments described herein relate to an improved information management system that can perform platform-agnostic containerized application data protection. In one embodiment, the information management system receives a user's credentials to a container orchestrator along with an indication of whether or not to deploy a backup pod. Using the user credentials, the information management system accesses the container orchestrator, and if the user has requested deployment of a backup pod on the user's cluster, the information management system may do so using a backup pod specification and allow the backup pod to perform data protection operations, using a platform-agnostic interface (e.g., container storage interface), for application data accessible by the user applications on the user's pod on the user's cluster. Alternatively, if the user has not requested deployment of a backup pod, the information management system may perform data protection operations using provider-specific interface.

The system, devices, and methods disclosed herein relate to a dynamic, robust method for choosing a “winner” in an active-active data storage network. In the systems and methods disclosed herein, two or more intelligent nodes within an active-active data storage network periodically exchange operational parameters in an ongoing negotiation regarding who should be the winner in the event of a communication failure within the network. The winner is chosen dynamically based on the operational parameters. A witness is kept apprised of the winner. In the event of a communication failure between the two nodes, the winner is chosen by the witness based on the most recently negotiated lock file reported by one or both of the nodes.

A first non-volatile dual in-line memory module (NVDIMM) of a first server and a second NVDIMM of a second server are armed during initial program load in a dual-server based storage system to configure the first NVDIMM and the second NVDIMM to retain data on power loss. Prior to initiating a safe data commit scan to destage modified data from the first server to a secondary storage, a determination is made as to whether the first NVDIMM is armed. In response to determining that the first NVDIMM is not armed, a failover is initiated to the second server.