Abstract: A computer-implemented method, according to one embodiment, includes: in response to a determination that an available capacity of one or more buffers in a primary cache is not outside a predetermined range, using the one or more buffers in the primary cache to satisfy all incoming I/O requests. In response to a determination that the available capacity of the one or more buffers in the primary cache is outside the predetermined range, one or more buffers in a secondary cache are allocated, and the one or more buffers in the secondary cache are used to satisfy at least some of the incoming I/O requests.

Abstract: A computer-implemented method, according to one embodiment, includes: receiving a data modification operation at a primary storage location. A determination is made whether data stored at the primary storage location is currently being synchronized with data stored at a secondary storage location. In response to determining that the data stored at the primary storage location is not currently being synchronized with the data stored at the secondary storage location: one or more instructions to satisfy the data modification operation are sent, and a bit in a first bitmap is set. Additionally, an extent that includes the modified track is determined, and a bit in a first summary bitmap is set. The bit set in the first bitmap corresponds to a track modified as a result of satisfying the data modification operation, while the bit in the first summary bitmap corresponds to the extent that includes the modified track.

Abstract: A computer-implemented method, according to one embodiment, includes: in response to a determination that an available capacity of one or more buffers in a primary cache is not outside a predetermined range, using the one or more buffers in the primary cache to satisfy all incoming I/O requests. In response to a determination that the available capacity of the one or more buffers in the primary cache is outside the predetermined range, one or more buffers in a secondary cache are allocated, and the one or more buffers in the secondary cache are used to satisfy at least some of the incoming I/O requests.

Abstract: A computer-implemented method, according to one approach, includes: receiving a stream of incoming I/O requests, all of which are satisfied using one or more buffers in a primary cache. However, in response to determining that the available capacity of the one or more buffers in the primary cache is outside a predetermined range: one or more buffers in the secondary cache are allocated. These one or more buffers in the secondary cache are used to satisfy at least some of the incoming I/O requests, while the one or more buffers in the primary cache are used to satisfy a remainder of the incoming I/O requests. Moreover, in response to determining that the available capacity of the one or more buffers in the primary cache is not outside the predetermined range: the one or more buffers in the primary cache are again used to satisfy all of the incoming I/O requests.

Abstract: Provided are a computer program product, system, and method for providing track access reasons for track accesses resulting in the release of prefetched cache resources for the track. A first request for a track is received from a process for which prefetched cache resources to a cache are held for a second request for the track that is expected. A track access reason is provided for the first request specifying a reason for the first request. The prefetched cache resources are released before the second request to the track is received. Indication is made in an unexpected released track list of the track and the track access reason for the first request.

Abstract: Provided are a computer program product, system, and method for providing track access reasons for track accesses resulting in the release of prefetched cache resources for the track. A first request for a track is received from a process for which prefetched cache resources to a cache are held for a second request for the track that is expected. A track access reason is provided for the first request specifying a reason for the first request. The prefetched cache resources are released before the second request to the track is received. Indication is made in an unexpected released track list of the track and the track access reason for the first request.

Abstract: A computer-implemented method, according to one approach, includes: receiving a stream of incoming I/O requests, all of which are satisfied using one or more buffers in a primary cache. However, in response to determining that the available capacity of the one or more buffers in the primary cache is outside a predetermined range: one or more buffers in the secondary cache are allocated. These one or more buffers in the secondary cache are used to satisfy at least some of the incoming I/O requests, while the one or more buffers in the primary cache are used to satisfy a remainder of the incoming I/O requests. Moreover, in response to determining that the available capacity of the one or more buffers in the primary cache is not outside the predetermined range: the one or more buffers in the primary cache are again used to satisfy all of the incoming I/O requests.

Abstract: An apparatus and method for copying data are disclosed. A data track to be replicated using a peer-to-peer remote copy (PPRC) operation is identified. The data track is encoded in a non-transitory computer readable medium disposed in a first data storage system. At a first time, a determination of whether the data track is stored in a data cache is made. At a second time, the data track is replicated to a non-transitory computer readable medium disposed in a second data storage system. The second time is later than the first time. If the data track was stored in the data cache at the first time, a cache manager is instructed to not demote the data track from the data cache. If the data track was not stored in the data cache at the first time, the cache manager is instructed that the data track may be demoted.

Abstract: A method for managing storage functions in a data replication environment is disclosed. In one embodiment, such a method includes continually monitoring for changes to a storage configuration at a secondary site. Upon detecting changes to the storage configuration at the secondary site, the method transmits remote metadata describing the changes to the primary site and stores the remote metadata at the primary site. The method then initiates a storage management function at the primary site which is mirrored to the secondary site. In order to perform the storage management function, the method reads the remote metadata at the primary site to determine the storage configuration at the secondary site. The method then performs the storage management function at the primary site in a way that takes into account the storage configuration at the secondary site. A corresponding apparatus, system, and computer-readable medium are also disclosed and claimed herein.

Abstract: A method for managing storage functions in a data replication environment is disclosed. In one embodiment, such a method includes continually monitoring for changes to a storage configuration at a secondary site. Upon detecting changes to the storage configuration at the secondary site, the method transmits remote metadata describing the changes to the primary site and stores the remote metadata at the primary site. The method then initiates a storage management function at the primary site which is mirrored to the secondary site. In order to perform the storage management function, the method reads the remote metadata at the primary site to determine the storage configuration at the secondary site. The method then performs the storage management function at the primary site in a way that takes into account the storage configuration at the secondary site.

Abstract: Provided are an article of manufacture, method, and system for using multiple sidefiles to buffer writes to primary storage volumes to transfer to corresponding secondary storage volumes in a mirror relationship. Information is provided on a mirror relationship for primary storage volumes and corresponding secondary storage volumes, wherein writes to the primary storage volumes are transferred to the secondary storage volumes according to the mirror relationship. A plurality of sidefiles are associated with the primary storage volumes in the mirror relationship. A write is received to one of the primary storage volumes in the mirror relationship. One of the sidefiles associated with the primary storage volume for which the write is received is selected and the write is buffered in the selected sidefile. Writes to the primary storage volumes buffered in the sidefiles are transferred to the corresponding secondary storage volumes.

Abstract: An apparatus, system, and method are disclosed for responsive acquisition of remote debug data. The apparatus for responsive acquisition of remote debug data is provided with a plurality of modules configured to detect an error on a local device, trigger a remote device to generate a remote debug data set in response to the error, and generate a local debug data set in response to the error. These modules in the described embodiments include a detection module, a trigger module, and a collection module.

Abstract: A system is disclosed that includes a host system to issue a write command, a primary storage controller to write data to a primary volume, and a secondary storage controller to mirror the data to a secondary volume. In the event the secondary storage controller is unable to mirror the data due to a busy state, a busy signal may be sent to the primary storage controller. The primary storage controller may initiate a timer in the event it receives the busy signal, and, in the event the busy state does not end before expiration of the timer, notify the host system that the primary and secondary volumes are in a suspended state. To alter the duration of the timer, the host system may be configured to dynamically alter the duration of the timer by sending a command to the primary storage controller.

Abstract: A system is disclosed that includes a host system to issue a write command, a primary storage device to write data to a primary volume, and a secondary storage device to mirror the data to a secondary volume. A task timer may be initiated upon sending the data from the primary storage device to the secondary storage device. The secondary storage device may also send an acknowledge signal to the primary storage device in the event it successfully mirrors the data to the secondary volume. In the event the acknowledge signal is not received before the timer expires, the primary storage device may notify the host system that the primary and secondary volumes are in a suspended state. To alter the duration of the timer, the host system may be further configured to dynamically alter the duration of the timer by sending a command to the primary storage device.

Abstract: An apparatus, system, and method are disclosed for detecting mismatches in a mirror volume. A receive module receives a start indicator from a primary storage system. The start indicator includes a starting location of a first block to be modified on a track in a secondary storage system. The first block corresponds to an identically located first block of a modified record in the primary storage system. The tracks the first blocks on the primary and secondary storage systems each comprise irregular count key data (“CKD”) tracks. A compare module compares the first block location indicated by the start indicator with block locations listed in track metadata. The track metadata describes user records on the irregular CKD tracks of the secondary storage system. An alert module generates an alert in response to the first block not aligning with a beginning block of a record on the secondary storage system.

Abstract: Provided are a method, system, and program for remote copying of updates to primary and secondary storage locations subject to a copy relationship. A first copy relationship is established between first and second storage locations in a first storage system and second storage system, respectively, wherein updates to the first storage locations are copied to the second storage locations. A second copy relationship is established between the first storage locations in the first copy relationship and third storage locations in a third storage system, wherein updates to the first storage locations are indicated in a first bitmap. A suspended third copy relationship is established between the second storage locations in the first copy relationship and the third storage locations, wherein updates to the second storage locations are indicated in a second bitmap.

Abstract: Provided are an article of manufacture, method, and system for using multiple sidefiles to buffer writes to primary storage volumes to transfer to corresponding secondary storage volumes in a mirror relationship. Information is provided on a mirror relationship for primary storage volumes and corresponding secondary storage volumes, wherein writes to the primary storage volumes are transferred to the secondary storage volumes according to the mirror relationship. A plurality of sidefiles are associated with the primary storage volumes in the mirror relationship. A write is received to one of the primary storage volumes in the mirror relationship. One of the sidefiles associated with the primary storage volume for which the write is received is selected and the write is buffered in the selected sidefile. Writes to the primary storage volumes buffered in the sidefiles are transferred to the corresponding secondary storage volumes.

Abstract: A system is disclosed that includes a host system to issue a write command, a primary storage controller to write data to a primary volume, and a secondary storage controller to mirror the data to a secondary volume. In the event the secondary storage controller is unable to mirror the data due to a busy state, a busy signal may be sent to the primary storage controller. The primary storage controller may initiate a timer in the event it receives the busy signal, and, in the event the busy state does not end before expiration of the timer, notify the host system that the primary and secondary volumes are in a suspended state. To alter the duration of the timer, the host system may be configured to dynamically alter the duration of the timer by sending a command to the primary storage controller.

Abstract: A system is disclosed that includes a host system to issue a write command, a primary storage device to write data to a primary volume, and a secondary storage device to mirror the data to a secondary volume. A task timer may be initiated upon sending the data from the primary storage device to the secondary storage device. The secondary storage device may also send an acknowledge signal to the primary storage device in the event it successfully mirrors the data to the secondary volume. In the event the acknowledge signal is not received before the timer expires, the primary storage device may notify the host system that the primary and secondary volumes are in a suspended state. To alter the duration of the timer, the host system may be further configured to dynamically alter the duration of the timer by sending a command to the primary storage device.

Abstract: An apparatus, system, and method are disclosed for responsive acquisition of remote debug data. The apparatus for responsive acquisition of remote debug data is provided with a plurality of modules configured to detect an error on a local device, trigger a remote device to generate a remote debug data set in response to the error, and generate a local debug data set in response to the error. These modules in the described embodiments include a detection module, a trigger module, and a collection module.