Abstract: 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.

Abstract: A metadata track stores metadata corresponding to both a first customer data track and a second customer data track. In response to receiving a first request to perform a write on the first customer data track from a two track write process, exclusive access to the first customer data track is provided to the first request, and shared access to the metadata track is provided to the first request. In response to receiving a second request to perform a write on the second customer data track from the two track write process, exclusive access to the second customer data track is provided to the second request, and shared access to the metadata track is provided to the second request prior to providing exclusive access to the metadata track to at least one process that is waiting for exclusive access to the metadata track.

Abstract: A metadata track stores metadata corresponding to both a first customer data track and a second customer data track. In response to receiving a first request to perform a write on the first customer data track from a two track write process, exclusive access to the first customer data track is provided to the first request, and shared access to the metadata track is provided to the first request. In response to receiving a second request to perform a write on the second customer data track from the two track write process, exclusive access to the second customer data track is provided to the second request, and shared access to the metadata track is provided to the second request prior to providing exclusive access to the metadata track to at least one process that is waiting for exclusive access to the metadata track.

Abstract: 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.

Abstract: A metadata track stores metadata corresponding to both a first customer data track and a second customer data track. In response to receiving a first request to perform a write on the first customer data track from a two track write process, exclusive access to the first customer data track is provided to the first request, and shared access to the metadata track is provided to the first request. In response to receiving a second request to perform a write on the second customer data track from the two track write process, exclusive access to the second customer data track is provided to the second request, and shared access to the metadata track is provided to the second request prior to providing exclusive access to the metadata track to at least one process that is waiting for exclusive access to the metadata track.

Abstract: 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.

Abstract: 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.

Abstract: A metadata track stores metadata corresponding to both a first customer data track and a second customer data track. In response to receiving a first request to perform a write on the first customer data track from a two track write process, exclusive access to the first customer data track is provided to the first request, and shared access to the metadata track is provided to the first request. In response to receiving a second request to perform a write on the second customer data track from the two track write process, exclusive access to the second customer data track is provided to the second request, and shared access to the metadata track is provided to the second request prior to providing exclusive access to the metadata track to at least one process that is waiting for exclusive access to the metadata track.

Abstract: Various embodiments provide computer program products for migrating data. One embodiment comprises receiving, from a first processor, data that is unprotected comprising a data integrity field; utilizing, by a second processor, a peer-to-peer remote copy (PPRC) application to add protection to the data to generate protected data; and subsequent to adding the protection, modifying a value in the data integrity field such that the value is different than an industry standard default value for protected data subsequent to adding the protection.

Abstract: Provided are a computer program product, system, and method for managing updates and copying data in a point-in-time copy relationship expressed as source logical addresses and target logical addresses. A copy relationship indicates a source set of a subset of source logical addresses to copy to a target set comprising a subset of target logical addresses. An update is received to a source logical address that has not been copied. Determinations are made of the target logical address corresponding to the source logical address to be updated according to the copy relationship, a target group of target logical addresses in the target set that include the determined target logical address, and the source logical addresses in the source set that correspond to the target logical addresses in the target group. The determined source logical addresses are copied to the target logical addresses in the determined target group.

Abstract: Provided are a computer program product, system, and method for processing a copy command indicating a source set comprising a subset of source logical addresses to copy to an indicated target set comprising a subset of target logical addresses. Complete is expected to be returned to the copy command in response to completing the copying of the source set to the target set. A point-in-time (PiT) copy establish command is generated in response to receiving the copy command, indicating the source and target sets in the copy command, The generated PiT copy command is executed to generate copy information indicating the source and target sets of source logical addresses and whether they have been copied to the target set. Complete is returned to the copy command after generating the copy information and before copying all the source logical addresses to the target logical addresses.

Abstract: Provided are a computer program product, system, and method for establishing a point-in-time copy relationship between source logical addresses and target logical addresses. A point-in-time (PiT) copy establish command specifies a source set comprising a subset of source logical addresses in at least one storage and a target set comprising a subset of target logical addresses in the at least one storage. The source set of source logical addresses are copied to the target set of target logical addresses. The source logical addresses map to source tracks and wherein the target logical addresses map to target tracks. Copy information is generated indicating whether the source logical addresses in the source set have been copied to the target set. Complete is returned to the PiT copy establish command after generating the copy information and before copying all the source logical addresses to the target logical addresses.

Abstract: Various embodiments provide computer program products for migrating data. One embodiment comprises receiving, from a first processor, data that is unprotected comprising a data integrity field; utilizing, by a second processor, a peer-to-peer remote copy (PPRC) application to add protection to the data to generate protected data; and subsequent to adding the protection, modifying a value in the data integrity field such that the value is different than an industry standard default value for protected data subsequent to adding the protection.

Abstract: Various embodiments provide computer program products for migrating data. One embodiment comprises an executable portion that receives, from a first processor, data that is unprotected; an executable portion that utilizes, by a second processor, a peer-to-peer remote copy (PPRC) application to add protection to the data to generate protected data; an executable portion that checks a CRC for the protected data when a request to migrate the protected data is received; and an executable portion that stores the protected data in the protected SCSI LUN.

Abstract: Provided are a computer program product, system, and method for establishing a point-in-time copy relationship between source logical addresses and target logical addresses. A point-in-time (PiT) copy establish command specifies a source set comprising a subset of source logical addresses in at least one storage and a target set comprising a subset of target logical addresses in the at least one storage. The source set of source logical addresses are copied to the target set of target logical addresses. The source logical addresses map to source tracks and wherein the target logical addresses map to target tracks. Copy information is generated indicating whether the source logical addresses in the source set have been copied to the target set. Complete is returned to the PiT copy establish command after generating the copy information and before copying all the source logical addresses to the target logical addresses.

Abstract: A mapping system and method that enables a secure reservation mode for a plurality of logical unit numbers of a storage system, generates a plurality of secret reservation keys, and instructs a distributed client to utilize at least one of the secret reservation keys to register with the storage system and to issue secure persistent reserves to the plurality of logical unit numbers.

Abstract: A mapping system and method that enables a secure reservation mode for a plurality of logical unit numbers of a storage system, generates a plurality of secret reservation keys, and instructs a distributed client to utilize at least one of the secret reservation keys to register with the storage system and to issue secure persistent reserves to the plurality of logical unit numbers.

Abstract: Various embodiments provide computer program products for migrating data. One embodiment comprises an executable portion that receives, from a first processor, data that is unprotected; an executable portion that utilizes, by a second processor, a peer-to-peer remote copy (PPRC) application to add protection to the data to generate protected data; an executable portion that checks a CRC for the protected data when a request to migrate the protected data is received; and an executable portion that stores the protected data in the protected SCSI LUN.

Abstract: Various embodiments provide systems and methods for migrating data. One system includes a small computer system interface logical unit number (SCSI LUN) configured to store protected data, a processor, and memory configured to store a peer-to-peer remote copy (PPRC) application. The processor is configured to check a block cyclic redundancy check (CRC) for the protected data when the processor receives a request to read the protected data. One method includes receiving unprotected data, utilizing, by a second processor, a peer-to-peer remote copy (PPRC) application to add protection to the data to generate protected data, checking a CRC for the protected data when a request to migrate the protected data is received, and storing the protected data in a protected SCSI LUN.

Abstract: Provided are a computer program product, system, and method for establishing a point-in-time copy relationship between source logical addresses and target logical addresses. A point-in-time (PiT) copy establish command specifies a source set comprising a subset of source logical addresses in at least one storage and a target set comprising a subset of target logical addresses in the at least one storage. The source set of source logical addresses are copied to the target set of target logical addresses. The source logical addresses map to source tracks and wherein the target logical addresses map to target tracks. Copy information is generated indicating whether the source logical addresses in the source set have been copied to the target set. Complete is returned to the PiT copy establish command after generating the copy information and before copying all the source logical addresses to the target logical addresses.