Techniques for processing data include: receiving a hierarchical structure of metadata (MD) pages for a logical device; and performing processing to copy data of the logical device from a source system to a target system. The first processing includes: determining a sequence of the MD pages in accordance with a depth first traversal of the hierarchical structure; defining a cache management policy in accordance with the sequence that indicates when to load the MD pages into a cache and when to remove the MD pages from the cache; loading MD pages into, and removing MD pages from, the cache in accordance with the cache management policy; and copying data pages stored at logical addresses of the logical device in an order in which the logical addresses are accessed using MD pages stored in the cache at various points in time in accordance with the cache management policy.

In one embodiment, a task control block (TCB) for allocating cache storage such as cache segments in a multi-track cache write operation may be enqueued in a wait queue for a relatively long wait period, the first time the task control block is used, and may be re-enqueued on the wait queue for a relatively short wait period, each time the task control block is used for allocating cache segments for subsequent cache writes of the remaining tracks of the multi-track cache write operation. As a result, time-out suspensions caused by throttling of host input-output operations to facilitate cache draining, may be reduced or eliminated. It is appreciated that wait classification of task control blocks in accordance with the present description may be applied to applications other than draining a cache. Other features and aspects may be realized, depending upon the particular application.

In one embodiment, an apparatus includes: a first memory controller to control access to a first memory, the first memory controller including a memory mirroring circuit, in response to a memory write request from a first processor socket for which the first memory comprises a primary memory region, to cause data associated with the memory write request to be written to the first memory and to send a shadow memory write request to a second memory to cause the second memory to write the data into a secondary memory region; and a shadow memory table including a plurality of entries each to store an association between a primary memory region and a secondary memory region. The memory mirroring circuit may access the shadow memory table to identify the secondary memory region. Other embodiments are described and claimed.

Provided are a computer program product, system, and method for using mirror indicators to indicate whether to mirror tracks in a data set in a primary volume mirrored to a secondary volume. A table includes a mirror indicator for each of a plurality of tracks in at least one data set in the primary volume indicating whether a track is to be mirrored to the secondary volume. In response to a write command of write data for one of the tracks in the primary volume, creating a record set in a cache for the primary volume including write data for the track to transfer to the secondary volume in response to the mirror indicator for the track indicating that the track is to be mirrored. The write data in the record set is transferred from the cache to the secondary volume.

Embodiments of the present disclosure relate to methods and apparatuses for caching data. A method comprises writing data into a first cache module on a first processor in response to receiving a first request for caching the data from a client module running on the first processor. The method further comprises transmitting, to the client module, a first indication that the data has been written into the first cache module. The method further comprises, in response to receiving from the client module a second request for synchronizing the data to a second processor, transmitting to the second processor a first command for causing the data to be written into a second cache module on the second processor. In addition, the method further comprises transmitting to the client module a second indication that the data has been synchronized.

Provided are a computer program product, system, and method for determining sectors of a track to stage into cache using a machine learning module. Performance attributes of system components affected by staging tracks from the storage to the cache are provided to a machine learning module. An output is received, from the machine learning module having processed the provided performance attributes, indicating a staging strategy indicating sectors of a track to stage into the cache comprising one of a plurality of staging strategies. Sectors of an accessed track that is not in the cache are staged into the cache according to the staging strategy indicated in the output.

A data access system has host computers having front-end controllers nFE_SAN connected via a bus or network interconnect to back-end storage controllers nBE_SAN, and physical disk drives connected via network interconnect to the nBE_SANs to provide a distributed, high performance, policy based or dynamically reconfigurable, centrally managed, data storage acceleration system. The hardware and software architectural solutions eliminate BE_SAN controller bottlenecks and improve performance and scalability. In an embodiment, the nBE_SAN (BE_SAN) firmware recognize controller overload conditions, informs Distributed Resource Manager (DRM), and, based on the DRM provided optimal topology information, delegates part of its workload to additional controllers. The nFE_SAN firmware and additional hardware using functionally independent and redundant CPUs and memory that mitigate single points of failure and accelerates write performance. The nFE_SAN and FE_SAN controllers facilitate Converged I/O Interface by simultaneously supporting storage I/O and network traffic.

A method for performing data access management of an all flash array (AFA) server and the AFA server operating according to the method are provided. The method includes: utilizing an upper layer program module running on a first node to detect whether any request from a client device of a user is received; in response to a write request, utilizing an intermediate layer program module to mirror data corresponding to the write request to a second node; and before the intermediate layer program module flushing the data to a lower layer program module, in response to the data being mirrored from a first volatile memory of the first node to a second volatile memory of the second node, utilizing the intermediate layer program module to send an acknowledgement to the client device without checking whether the data has been protected in any non-volatile memory of any of the multiple nodes.

Provided are a computer program product, system, and method for using a mirroring cache list to mirror modified tracks for a primary storage in a cache to a secondary storage. Indication is made of a modified track for the primary storage stored in the cache in a mirroring cache list. The mirroring cache list is processed to select modified tracks in the cache to transfer to the secondary storage that have not yet been transferred. The selected modified tracks are transferred to the secondary storage. Indication of a modified track is removed from the mirroring cache list in response to demoting the modified track from the cache.

Provided are a computer program product, system, and method for indicating extents of tracks in mirroring queues based on information gathered on tracks in extents in cache. Extent information on an extent of tracks in a cache indicated in an active cache list is processed in response to destaging a track from the active cache list to add to a demote list used to determine tracks to remove from the cache. The extent information is related to a number of modified tracks in an extent destaged from the active cache list. The extent information for the extent is used to determine one of a plurality of mirroring queues to indicate the extent including modified tracks. A mirroring queue having a higher priority than another mirroring queue is processed at a higher rate to determine extents of tracks to mirror from the cache to the secondary storage.