A first drive volume formed on a disk within a drive enclosure. The first drive volume is read from and written to by a first head that is moved by a first actuator, A second drive volume is formed on the one or more disks. The second volume is read from and written to by a second head that is moved via a second actuator within the drive enclosure. The second actuator is separate and independent from the first actuator. Data of the first drive volume is duplicated onto the second drive volume, Background validation operations are performed on the second drive volume instead of the first volume.

Systems and methods for re-aligning data replication configuration of a cross-site storage solution after a failover are provided. According to one embodiment, after a failover, the new primary distributed storage system orchestrates flipping of the data replication configuration of a peered consistency group (CG) to reestablish zero RPO and zero RTO protections for the peered CG. The primary causes the secondary distributed storage system to perform an atomic database operation on its remote configuration database to (i) delete an existing source configuration that identifies the secondary as a source of data replication; and (ii) persist a new destination configuration identifying the secondary as a destination of data replication. Then, the primary performs an atomic database operation on its local configuration database to (i) delete an existing destination configuration identifying the primary as the destination; and (ii) persist a new source configuration identifying the distributed storage system as the source.

A storage system has a cluster structure in which a node is connected with a different node, the node having a volatile memory for storing first update data from a host and a first non-volatile memory for storing second copy data of second update data from the host to the different node, and having a copy management processing unit for storing first copy data of the first update data into a second non-volatile memory of the different node, and a storage service processing unit for transmitting, to the host, a response with respect to an update request of the first update data in response to the storage of the first copy data of the first update data by the copy management processing unit into the second non-volatile memory of the different node.

The present disclosure includes apparatuses and methods for proactive corrective actions in memory based on a probabilistic data structure. A number of embodiments include a memory, and circuitry configured to input information associated with a subset of data stored in the memory into a probabilistic data structure and proactively determine, at least partially using the probabilistic data structure, whether to take a corrective action on the subset of data stored in the memory.

Mirrored byte addressable storage is disclosed. For example, first and second persistent memories store first and second pluralities of pages, both associated with a plurality of page states in a mirror state log in a third persistent memory. A mirror engine executing on a processor with a processor cache detects a write fault associated with the first page of the first plurality of pages and in response, updates a first page state to a dirty-nosync state. A notice of a flush operation of the processor cache associated with first data is received. The first data becomes persistent in the first page of the first plurality of pages after the flush operation; then the first page state is updated to a clean-nosync state. The first data is then copied to the first page of the second plurality of pages; then the first page state is updated to a clean-sync state.

The present disclosure includes apparatuses and methods for proactive corrective actions in memory based on a probabilistic data structure. A number of embodiments include a memory, and circuitry configured to input information associated with a subset of data stored in the memory into a probabilistic data structure and proactively determine, at least partially using the probabilistic data structure, whether to take a corrective action on the subset of data stored in the memory.

A controlling device: receives state information indicating the state of a first storage region and the state of a second storage region for mirroring the first storage region; detects an error of an input and output process executed on the first storage region; executes, in response to the error, a first process if the first storage region is in a read-write mode, the first process including determining the states of the first and second storage regions, and selecting, based on the determined states, either one of executing the input and output process on the second storage region or stopping the input and output process executed on the first and second storage regions; and executes, in response to the error, a second process if the first storage region is in a read-only mode, the second process including executing the input and output process on the second storage region.

In a storage system, a processor divides a plurality of sections that constitute a physical storage area in a storage device into primary sections and secondary sections, associates one primary section and one secondary section with each other and then manages the associated primary section and secondary section, and writes data having been written to a primary section also to a secondary section corresponding to the primary section.

An SSD has a plurality of dies, with each die having a storage capacity. The storage capacity of each die is divided into a primary capacity and a spare capacity. A primary die has a maximum primary capacity, and a sum of the spare capacities of the remaining dies is greater than the maximum primary capacity. Data stored on the SSD is distributed among the primary capacities of the dies. When a failure of a first die is detected, data stored on the failed first die is migrated to the spare capacity of at least one of the remaining dies.

Digital objects are stored and accessed within a fixed content storage cluster by using a page mapping table and a pages index. A stream is read from the cluster by using a portion of its unique identifier as a key into the page mapping table. The page mapping table indicates a node holding a pages index indicating where the stream is stored. A stream is written by storing the stream on any suitable node and then updating a pages index stored within the cluster responsible for knowing the location of digital objects having unique identifiers that fall within a particular address range. The cluster recovers from a node failure by first replicating streams from the failed node and reallocating a page mapping table to create a new pages index. The remaining nodes send records of the unique identifiers corresponding to objects they hold to the new pages index.