A system includes reception of a first request to synchronize content from the persistent memory system to the volatile memory system, and, in response to the first request, retrieval of the content from the persistent memory system and store the content in the volatile memory system. A create, read, update or delete operation is performed on the content stored in the volatile memory system to generate modified content in the volatile memory system, a second request to synchronize content is received from the volatile memory system to the persistent memory system, and, in response to the second request, the modified content is retrieved from the volatile memory system and the modified content is stored in the persistent memory system.

With omission of a duplication process of compressed data, a cache access frequency is reduced to improve throughput. A storage system includes first and second control units and a storage drive. Upon receiving a data write command, the first control unit stores data to be subjected to the write command in a first cache area of the first control unit, and stores the data in a second cache area of the second control unit to perform duplication, and upon completion of the duplication, the first control unit transmits a response indicating an end of write, performs a predetermined process on the data to be subjected to the write command, stores the data in a buffer area, reads the data stored in the buffer area, and transmits the read data to the storage drive.

A multi-core processor having a first operation mode in which processors perform the same task and a second operation mode in which the processors perform different tasks includes first and second processors configured to write an operation mode value to a first register or second register when a function called in executed software requests the first or second operation mode, a manager configured to assign core IDs of the first and second processors according to the operation mode value stored in the first register or second register, and a reset controller configured to reset the first and second processors in response to the function, wherein the manager assigns the same core ID to the first and second processors when the operation mode value indicates the first operation mode, and allocates different core IDs to the first and second processors when the operation mode value indicates the second operation mode.

Embodiments of the present disclosure provide a method, device and computer program product for validating a cache file. In an embodiment, a reference cache file associated with the backed up data is divided into a plurality of reference segments. Reference check information is generated for the respective reference segments of the plurality of reference segments, and the generated reference check information is stored. In response to the initiating of a backup job, the stored reference check information is used to validate the cache file.

Techniques are described for processing multi-page write operations to maintain write level consistency. A multi-page write spanning multiple cache pages is directed to a target device and received on a first data storage system where writes to the target device are synchronously replicated to a second data storage system. On the first data storage system, each of the multiple cache pages may be synchronously replicated to the second data storage system. A lock on each of the cache pages is not released until an acknowledgement is received regarding successful replication of the cache page. On the second data storage system, requests to replicate the multiple cache pages containing write data of the multi-page write are received and processed using locks of corresponding cache pages on the second data storage system. Such techniques also handle concurrent reads and/or writes. Deadlock detection and resolution processing may be performed for concurrent writes.

Provided are techniques for performing a recovery copy command to restore a safeguarded copy backup to a production volume. In response to receiving a recovery copy command, a production target data structure is created. A read operation is received for data for a storage location. In response to determining that the data for the storage location is in a cache of a host and a generation number is greater than a recovery generation number, the data is read from the cache. In response to determining at least one of that the data for the storage location is not in the cache and that the generation number is not greater than the recovery generation number, the data is read from one of the production volume and a backup volume based on a value of an indicator for the storage location in the production target data structure.

A computer system including: a first computer including a first processor and a first nonvolatile memory; and a second computer including a second processor and a second nonvolatile memory in which the second computer is connected to the first computer. The first computer includes a redundant hardware that, on receiving a write command from the first processor, writes the write data of the write command both into the first nonvolatile memory and into the second computer.

Provided are a computer program product, system, and method for populating a second cache with tracks from a first cache when transferring management of the tracks from a first node to a second node. Management of a first group of tracks in the storage managed by the first node is transferred to the second node managing access to a second group of tracks in the storage. After the transferring the management of the tracks, the second node manages access to the first and second groups of tracks and caches accessed tracks from the first and second groups in the second cache of the second node. The second cache of the second node is populated with the tracks in a first cache of the first node.

Technologies are provided for storing data by alternating the performance of data write operations using multiple clusters of storage devices. Data is written to internal buffers of storage devices in one cluster while data stored in buffers of storage devices in another cluster is transferred to the storage devices' permanent storages. When available buffer capacity in a cluster falls below a specified threshold, data write commands are no longer sent the cluster and the storage devices in the cluster transfer data stored in their buffers to their permanent storages. While the data is being transferred, data write commands are transmitted to other clusters. When the data transfer is complete, the storage devices in the cluster can be scheduled to receive data write commands again. A cluster can be selected for performing a given data write request by matching the attributes of the cluster to parameters of the data write request.

A method controlling near caches in a distributed cache environment including distributed cache servers is provided. The method includes steps of: a specific distributed cache server among the distributed cache servers, if a request signal for original cache data is obtained from a client node, transmitting replicated cache data for the original cache data to the client node, to support the client node to store and refer to the replicated cache data in its corresponding near cache storage part, and managing a reference map with a correspondence between the client node referring to the replicated cache data, and the original cache data; and if the original cache data is changed, checking the number of the client nodes referring to the replicated cache data by referring to the reference map, and invalidating the replicated cache data according to the number of the checked client nodes.