Abstract: A method for improving destage performance to a RAID array is disclosed. In one embodiment, such a method periodically scans a cache for first strides that are ready to be destaged to a RAID array. While scanning the cache, the method identifies second strides that are not currently ready to be destaged to the RAID array, but will likely be ready to be destaged during a subsequent scan of the cache. The method initiates preemptive staging of any missing data of the second strides from the RAID array into the cache in preparation for the subsequent scan. Upon occurrence of the subsequent scan, the method destages, from the cache, the second strides from the cache to the RAID array. A corresponding system and computer program product are also disclosed.

Abstract: A computer-implemented method, according to one approach, is for converting an existing storage pool into an intended storage pool in place. The computer-implemented method includes: reordering volume extents in the existing storage pool such that physical rank extents of the volumes align with boundaries between rank extents of the intended storage pool. The ranks in the existing storage pool are also converted from first rank extent sizes to second rank extent sizes. Moreover, in response to converting the ranks in the existing storage pool, for each of the volumes: a temporary pause/lock is performed on a volume segment table (VST) entry which corresponds to the given volume, and the VST entry is populated with a new structure which corresponds to the respective second rank extent size.

Abstract: A storage controller is configured to perform a full stride destage, a strip destage, and an individual track destage. A machine learning module receives a plurality of inputs corresponding to a plurality of factors that affect performance of data transfer operations and preservation of drive life in the storage controller. In response to receiving the inputs, the machine learning module generates a first output, a second output, and a third output that indicate a preference measure for the full stride destage, the strip destage, and the individual track destage respectively.

Abstract: A first score corresponding to a full stride destage, a second score corresponding to a strip destage, and a third score corresponding to an individual track destage are computed, wherein the first score, the second score, and the third score are computed for a group of Input/Output (I/O) operations based on a first metric and a second metric, wherein the first metric is configured to affect a performance of data transfers, and wherein the second metric is configured to affect a drive life. A determination is made of a type of destage to perform based on the first score, the second score, and the third score.

Abstract: A method for improving destage performance to a RAID array is disclosed. In one embodiment, such a method periodically scans a cache for first strides that are ready to be destaged to a RAID array. While scanning the cache, the method identifies second strides that are not currently ready to be destaged to the RAID array, but will likely be ready to be destaged during a subsequent scan of the cache. The method initiates preemptive staging of any missing data of the second strides from the RAID array into the cache in preparation for the subsequent scan. Upon occurrence of the subsequent scan, the method destages, from the cache, the second strides from the cache to the RAID array. A corresponding system and computer program product are also disclosed.

Abstract: A first score corresponding to a full stride destage, a second score corresponding to a strip destage, and a third score corresponding to an individual track destage are computed, wherein the first score, the second score, and the third score are computed for a group of Input/Output (I/O) operations based on a first metric and a second metric, wherein the first metric is configured to affect a performance of data transfers, and wherein the second metric is configured to affect a drive life. A determination is made of a type of destage to perform based on the first score, the second score, and the third score.

Abstract: A storage controller is configured to perform a full stride destage, a strip destage, and an individual track destage. A machine learning module receives a plurality of inputs corresponding to a plurality of factors that affect performance of data transfer operations and preservation of drive life in the storage controller. In response to receiving the inputs, the machine learning module generates a first output, a second output, and a third output that indicate a preference measure for the full stride destage, the strip destage, and the individual track destage respectively.

Abstract: A computer-implemented method, according to one approach, is for converting an existing storage pool into an intended storage pool in place. The computer-implemented method includes: identifying a request to convert the existing storage pool having a first extent size into the intended storage pool having a second extent size, where the first extent size is larger than the second extent size. For each volume in the existing storage pool: a temporary pause/lock is performed on a volume segment table (VST) entry which corresponds to the given volume, and a new structure is applied to the VST entry. The new structure divides existing physical extents associated with the VST entry into two or more smaller physical extents. Furthermore, for each of the ranks in the existing storage pool, the given rank is converted from the first extent size to the second extent size.

Abstract: A computer-implemented method, according to one approach, is for converting an existing storage pool into an intended storage pool in place. The computer-implemented method includes: reordering volume extents in the existing storage pool such that physical rank extents of the volumes align with boundaries between rank extents of the intended storage pool. The ranks in the existing storage pool are also converted from first rank extent sizes to second rank extent sizes. Moreover, in response to converting the ranks in the existing storage pool, for each of the volumes: a temporary pause/lock is performed on a volume segment table (VST) entry which corresponds to the given volume, and the VST entry is populated with a new structure which corresponds to the respective second rank extent size.

Abstract: A computer-implemented method, according to one approach, is for converting an existing storage pool into an intended storage pool in place. The computer-implemented method includes: identifying a request to convert the existing storage pool having a first extent size into the intended storage pool having a second extent size, where the first extent size is larger than the second extent size. For each volume in the existing storage pool: a temporary pause/lock is performed on a volume segment table (VST) entry which corresponds to the given volume, and a new structure is applied to the VST entry. The new structure divides existing physical extents associated with the VST entry into two or more smaller physical extents. Furthermore, for each of the ranks in the existing storage pool, the given rank is converted from the first extent size to the second extent size.

Abstract: A computer-implemented method, according to one approach, includes: identifying a request to convert an existing storage pool having a smaller first rank extent size into an intended storage pool having a larger second rank extent size. Volume extents in the existing storage pool are reordered such that physical rank extents of the volumes align with boundaries between the rank extents of the intended storage pool. Each of the ranks in the existing storage pool are converted from the first to the second rank extent size. Thereafter, for each of the volumes: a temporary pause/lock is performed on a VST entry which corresponds to the given volume, and an existing structure associated with the VST entry which corresponds to the first rank extent size is removed. Furthermore, the VST entry is populated with a new structure which corresponds to the second rank extent size.

Abstract: For preventing data loss in storage systems a detection is made that a storage device in a plurality of storage devices is experiencing a malfunction. The type of malfunction is determined. A SMART rebuilding technique, a normal building technique, a data migration technique, or a user data backup technique is selected to preserve the data in the storage device based on the determined type of the malfunction. The selected technique is performed on the storage device.

Abstract: For preventing data loss in storage systems, a detection is made that a storage device in a plurality of storage devices is experiencing a malfunction. The type of malfunction is determined. A SMART rebuilding technique, a normal building technique, a data migration technique, or a user data backup technique is selected to preserve the data in the storage device based on the determined type of the malfunction. The selected technique is performed on the storage device.

Abstract: For preventing data loss in storage systems, a detection is made that a storage device in a plurality of storage devices is experiencing a malfunction. The type of malfunction is determined. A SMART rebuilding technique, a normal building technique, a data migration technique, or a user data backup technique is selected to preserve the data in the storage device based on the determined type of the malfunction. The selected technique is performed on the storage device.

Abstract: For preventing data loss in storage systems, a detection is made that a storage device in a plurality of storage devices is experiencing a malfunction. The type of malfunction is determined. A SMART rebuilding technique, a normal building technique, a data migration technique, or a user data backup technique is selected to preserve the data in the storage device based on the determined type of the malfunction. The selected technique is performed on the storage device.

Abstract: Provided are a method, system, and article of manufacture for error checking addressable blocks in storage. Addressable blocks of data are stored in a storage in stripes, wherein each stripe includes a plurality of data blocks for one of the addressable blocks and at least one checksum block including checksum data derived from the data blocks for the addressable block. A write request is received to modify data in one of the addressable blocks. The write and updating the checksum are performed in the stripe having the modified addressable block. An indication is made to perform an error checking operation on the stripe for the modified addressable block in response to the write request, wherein the error checking operation reads the data blocks and the checksum in the stripe to determine if the checksum data is accurate. An error handling operation is initiated in response to determining that the checksum data is not accurate.

Abstract: Provided are a method, system, and program for destaging a track from cache to a storage device. The destaged track is retained in the cache. Verification is made of whether the storage device successfully completed writing data. Indication is made of destaged tracks eligible for removal from the cache that were destaged before the storage device is verified in response to verifying that the storage device is successfully completing the writing of data.

Abstract: An apparatus and method to manage redundant non-volatile storage (“NVS”) data backups in a data storage system comprising (n) clusters, wherein each cluster comprises a processor and a cache, and wherein each cache comprises a first NVS portion and a second NVS portion, wherein the method configures, for each value of (i), a primary NVS backup for an (i)th cluster, where that (i)th primary NVS backup comprises a first NVS portion of a cache disposed in an (i+1)th modulo (n) cluster, wherein (i) is greater than or equal to 0 and less than (n). The method further configures, for each value of (i), a secondary NVS backup for an (i)th cluster, where that (i)th secondary NVS backup comprises a second NVS portion of a cache disposed in an (i+2)th modulo (n) cluster.

Abstract: A method to access a data in a RAID array comprising a plurality of data storage media, wherein information is written to said plurality of data storage media using a RAID configuration, wherein the method receives from a requester a command comprising a data access priority indicator. If a RAID rebuild is in progress, the method determines if the data access priority indicator is set. If the data access priority indicator is set, the method executes a command selected from the group consisting of writing information to the target logical block array range, and returning to the requestor information read from the target logical block array range.

Abstract: Provided are a method, system, and article of manufacture for using device status information to takeover control of devices assigned to a node. A first processing unit communicates with a second processing unit. The first processing unit uses a first device accessible to both the first and second processing units and the second processing unit uses a second device accessible to both the first and second processing units. The first processing unit receives status on the second device from the first device indicating whether the second device is available or unavailable. The first processing unit detects a failure of the second processing unit and determines from the received status on the second device whether the first device is available in response to detecting the failure of the second processing unit.