Methods, computing systems and computer program products implement embodiments of the present invention that include configuring a first storage system to mirror first storage regions to corresponding second storage regions in a second storage system via a first data connection, and to mirror the first storage regions to corresponding third storage regions in a third storage system via a second data connection. Upon the second storage system receiving, subsequent to detecting a failure of the first storage system, a host I/O request to retrieve data from a given second storage region and determining that the respective timestamp of the corresponding third storage region on the third storage system is more recent than the respective timestamp of the given second storage region on the second storage system, the second storage system retrieves, via a third data connection, the data from the corresponding third storage region on the third storage system.

Methods, apparatus and computer program products implement embodiments of the present invention that include conveying first data from local regions of a local volume of a local storage system to a remote storage system having a remote volume with remote regions in a one-to-one correspondence with the local regions. While conveying the first data, a request is received to update a given local region, and the given local region is marked.

A method for remotely accessing data and a local apparatus using the method are provided. An embedded controller determines whether a power management state of the local apparatus is switched to a power saving state when the embedded controller receives a remote control signal through a network unit from a cloud server. The embedded controller activates a first switch unit to switch, such that data received from the network unit is transferred to a storage unit.

Disclosed herein are methods, systems, and processes to adjust replication operations in a distributed environment. A set of replicated data is received from a first appliance as a result of a replication operation. The replication operation is initiated by the first appliance and the set of replicated data includes a first timestamp. A write operation is performed to store the set of replicated data and a second timestamp is recorded. Recovery point information is generated based on the first timestamp and the second timestamp. The recovery point information is configured to be utilized in adjusting replication parameters of a subsequent replication operation.

In certain systems disclosed herein, a distributed data monitoring and management system is provided that can replicate a distributed storage environment. The distributed data monitoring and management system can intelligently and automatically configure data access nodes to form a structure that matches the distributed storage environment. By matching the structure of the distributed storage environment, the distributed structure of the data may be maintained, enabling the data to be backed up from and/or restored to the distributed storage environment and/or migrated to another distributed storage environment without altering the distribution of the data. Further, embodiments herein enable the transfer of data from a non-distributed environment to a distributed storage environment. Thus, in some cases, an entity can migrate data from a local storage structure to a network-based distributed storage structure.

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.

A method and system for incremental backup is disclosed. The method includes writing a first update to a secondary node and writing a second update to the secondary node. The secondary node comprises a replication storage group (RSG). Further, the order in which the updates are written at the secondary node is consistent with the order in which the updates were written at a primary node.

In certain systems disclosed herein, a distributed data monitoring and management system is provided that can replicate a distributed storage environment. The distributed data monitoring and management system can intelligently and automatically configure data access nodes to form a structure that matches the distributed storage environment. By matching the structure of the distributed storage environment, the distributed structure of the data may be maintained, enabling the data to be backed up from and/or restored to the distributed storage environment and/or migrated to another distributed storage environment without altering the distribution of the data. Further, embodiments herein enable the transfer of data from a non-distributed environment to a distributed storage environment. Thus, in some cases, an entity can migrate data from a local storage structure to a network-based distributed storage structure.

A first control unit of a first control device executes: a synchronous copy process for writing data from a host device into a first storage medium, transmitting the data to a second control device, and replying to the host device; a storage process for storing the data written in the first storage medium into a first region, instructing the second control device on a buffer switch when a predetermined condition is satisfied, and switching a storage destination to a second region; and an asynchronous copy process for transmitting the data in the first region and the second region to a third control device at a time, respectively. A second control unit stores the data transmitted from the first control unit in a second storage medium and a third region, and when the buffer switch is instructed, stores the data in the second storage medium and a fourth region.

A plurality of arrays of storage devices, each providing dual storage device redundancy, is provided. The plurality of arrays of storage devices includes a plurality of mirrored sets of primary storage devices, each including an even number of at least two or more primary storage devices. Each of the mirrored sets of primary storage devices stores a first and a second copy of data. The plurality of arrays of storage devices also includes a secondary storage device, which is a single physical storage device that stores a third copy of the data stored on each of the plurality of mirrored sets of primary storage devices. The secondary storage device has at least the capacity to store the data stored on the plurality of mirrored sets of primary storage devices. Dual storage device redundancy preserves data if data cannot be read from one or two physical storage devices in any array.