The disclosed computer-implemented method for marking application-consistent points-in-time may include intercepting, by an I/O filter, a write request from a guest virtual machine to a virtual machine disk and queueing the write request in an I/O filter queue. The method may include sending the write request to the virtual machine disk and receiving a write completion message from the virtual machine disk. The method may also include sending, in response to the write completion message, the write request to an I/O daemon, and queueing the write request in an I/O daemon queue. The method may further include sending the write completion message to the guest virtual machine, and sending the write request to a backup gateway such that the backup gateway mimics writes to the virtual machine disk. Various other methods, systems, and computer-readable media are also disclosed.

Migrating a source volume from a source appliance to a destination appliance, wherein the source volume is assigned to an asymmetric namespace access (ANA) group and initially exposed to a host computer as accessible at the source appliance, includes creating a destination volume on the destination appliance and expanding the ANA group to include the destination volume, with the ANA group initially exposing the destination volume as inaccessible to the host computer at the destination appliance. Subsequently, the destination volume is synchronized to the source volume and then a cutover is performed that includes (i) copying volume metadata including host reservations from the source volume to the destination volume, and (ii) changing the ANA group to expose the source volume as inaccessible at the source appliance and the destination volume as accessible at the destination appliance.

A secondary location is configured as a recovery service for a primary location of the service. The secondary location is maintained in a warm state that is configured to replace the primary location in a case of a failover. During normal operation, the secondary location is automatically updated to reflect a current state of the primary location that is actively servicing user load. Content changes to the primary location are automatically reflected to the secondary location. System changes applied to the primary location are automatically applied to the secondary location. For example, removing/adding machines, updating machine/role assignments, removing adding/database are automatically applied to the secondary location such that the secondary location substantially mirrors the primary location. After a failover to the secondary location, the secondary location becomes the primary location and begins to actively service the user load.

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.

Consistency groups are asynchronously copied to a remote computational device, from a local computational device, wherein point in time copy operations are performed at the local computational device while the consistency groups are being asynchronously copied to the remote computational device. Indicators are stored at the remote computational device to identify those point in time copy operations that are to be restored as part of a recovery operation performed at the remote computational device in response to a failure of the local computational device.

A data replication method includes obtaining differential data information corresponding to differential data, where the differential data information includes a storage address of the differential data, and a determining value of the differential data, replicating the differential data from the primary volume to the secondary volume according to the storage address of the differential data that is located in the primary volume when the determining value is not less than a preset threshold, and taking a snapshot for the primary volume when the determining value is less than the preset threshold and replicating the differential data to the secondary volume.

A data storage system includes multiple head nodes and data storage sleds. Volume data is replicated between a primary and one or more secondary head nodes for a volume partition and is further flushed to a set of mass storage devices of the data storage sleds. Volume metadata is maintained in a primary and one or more secondary head nodes for a volume partition and is updated in response to volume data being flushed to the data storage sleds. Also, the primary and secondary head nodes store check-points of volume metadata to the data storage sleds, wherein in response to a failure of a primary or secondary head node for a volume partition, a replacement secondary head node for the volume partition recreates a secondary replica for the volume partition based, at least in part, on a stored volume metadata checkpoint.

Failover methods and systems for a networked storage environment are provided. A metadata data structure is generated, before starting a replay of entries at a log stored in a non-volatile memory of a second storage node, during a failover operation initiated in response to a failure at a first storage node. The second storage node operates as a partner node of the first storage node, and the metadata structure stores a metadata attribute of each log entry. Furthermore, the metadata attribute of each log entry is persistently stored. The persistently stored metadata attribute is used to respond to a read request received during the replay by the second storage node, while a write request metadata attribute of a write request is used for executing the write request received by the second storage node during the replay.

Systems and methods which provide for managing multiple mirror resources in a storage distribution network are provided. In some embodiments, a system provides for both high availability and disaster recovery functionality at different mirroring locations. Other embodiments may provide for multiple high availability and/or multiple disaster recovery mirror resources. These mirror resources are operated in a heterogeneous manner in the sense that each have its own transport, protocol, and the like, but are configured function cooperatively or as a single mirror with respect to mirroring a primary node. Embodiments may provide for the mirroring and resynchronization of mirrored resources in the event of a communication loss with a particular resource without ceasing the mirroring operations to other resources.

Systems and methods are disclosed to improve disaster recovery by implementing a scalable low-loss disaster recovery for a data store. The disaster recovery system enables disaster recovery for a linearizable (e.g., externally consistent) distributed data store. The disaster recovery system also provides for a small lag on the backup site relative to the primary site, thereby reducing the data loss by providing a smaller data loss window compared to traditional disaster recovery techniques. The disaster recovery system implements a timestamp for log records based on a globally synchronized clock. The disaster recovery system also implements a watermark service that updates a global watermark timestamp that a backup node uses to apply log records.