Abstract: A data storage subsystem having a plurality of data compression engines configured to compress data, each having a different compression algorithm. A data handling system is configured to determine a present rate of access to data; select at least one sample of data; determine the greatest degree of compression of said data compression engines; determine the compression ratios of the operated data compression engines with respect to the selected sample(s); compressing said selected at least one sample with a plurality of said data compression engines at said selected tier; operate a selected data compression engines with respect to the selected sample and determine the greatest degree of compression of the data compression engines; compress the data from which the sample was selected with one of the operated data compression engines determined to have the greatest degree of compression; and store the compressed data in data storage repositories.

Abstract: A read/write ratio for each of a plurality of data segments classified in a hot category as hot data segments is determined. Each of the plurality of hot data segments is ordered by the read/write ratio in a descending order. Each of a plurality of available SSD devices is ordered by a remaining life expectancy in an ascending order. Those of the plurality of hot data segments are matched with those of the plurality of hot data segments with those of the plurality of available SSD devices such that a hot data segment having a higher read/write ratio is provided to an SSD device having a smaller remaining life expectancy than another hot data segment having a lower read/write ratio.

Abstract: A read/write ratio for each of a plurality of data segments classified in a hot category as hot data segments is determined. Each of the plurality of hot data segments is ordered by the read/write ratio in a descending order. Each of a plurality of available SSD devices is ordered by a remaining life expectancy in an ascending order. Those of the plurality of hot data segments are matched with those of the plurality of hot data segments with those of the plurality of available SSD devices such that a hot data segment having a higher read/write ratio is provided to an SSD device having a smaller remaining life expectancy than another hot data segment having a lower read/write ratio.

Abstract: Provided are a method, system, and article of manufacture for iterative data secret-sharing transformation and reconversion. In one aspect, data secret-sharing transformation and reconversion is provided in which each bit of an input stream of bits of data is split, on a bit by bit basis, into a pair of secret-sharing bits, and the secret-sharing bits of each pair of secret-sharing bits are separated into separate streams of secret-sharing bits. In this manner, one secret-sharing bit of each pair of secret-sharing bits may be placed in one stream of secret-sharing bits and the other secret-sharing bit of each pair may be placed in another stream of secret-sharing bits different from the one stream of secret-sharing bits. Confidentiality of the original input stream may be protected in the event one but not both streams of secret-sharing bits is obtained by unauthorized personnel.

Abstract: A read/write ratio for each of a plurality of data segments classified in a hot category as hot data segments is determined. Each of the plurality of hot data segments is ordered by the read/write ratio in a descending order. Each of a plurality of available SSD devices is ordered by a remaining life expectancy in an ascending order. Those of the plurality of hot data segments are matched with those of the plurality of hot data segments with those of the plurality of available SSD devices such that a hot data segment having a higher read/write ratio is provided to an SSD device having a smaller remaining life expectancy than another hot data segment having a lower read/write ratio.

Abstract: A data storage subsystem having a plurality of data compression engines configured to compress data, each having a different compression algorithm. A data handling system is configured to determine a present rate of access to data; select at least one sample of data; determine the greatest degree of compression of said data compression engines; determine the compression ratios of the operated data compression engines with respect to the selected sample(s); compressing said selected at least one sample with a plurality of said data compression engines at said selected tier; operate a selected data compression engines with respect to the selected sample and determine the greatest degree of compression of the data compression engines; compress the data from which the sample was selected with one of the operated data compression engines determined to have the greatest degree of compression; and store the compressed data in data storage repositories.

Abstract: Provided are a method, system, and article of manufacture for iterative data secret-sharing transformation and reconversion. In one aspect, data secret-sharing transformation and reconversion is provided in which each bit of an input stream of bits of data is split, on a bit by bit basis, into a pair of secret-sharing bits, and the secret-sharing bits of each pair of secret-sharing bits are separated into separate streams of secret-sharing bits. In this manner, one secret-sharing bit of each pair of secret-sharing bits may be placed in one stream of secret-sharing bits and the other secret-sharing bit of each pair may be placed in another stream of secret-sharing bits different from the one stream of secret-sharing bits. Confidentiality of the original input stream may be protected in the event one but not both streams of secret-sharing bits is obtained by unauthorized personnel.

Abstract: Provided are a method, system, and article of manufacture for iterative data secret-sharing transformation and reconversion. In one aspect, data secret-sharing transformation and reconversion is provided in which each bit of an input stream of bits of data is split, on a bit by bit basis, into a pair of secret-sharing bits, and the secret-sharing bits of each pair of secret-sharing bits are separated into separate streams of secret-sharing bits. In this manner, one secret-sharing bit of each pair of secret-sharing bits may be placed in one stream of secret-sharing bits and the other secret-sharing bit of each pair may be placed in another stream of secret-sharing bits different from the one stream of secret-sharing bits. Confidentiality of the original input stream may be protected in the event one but not both streams of secret-sharing bits is obtained by unauthorized personnel.

Abstract: Provided are a method, system, and article of manufacture for iterative data secret-sharing transformation and reconversion. In one aspect, data secret-sharing transformation and reconversion is provided in which each bit of an input stream of bits of data is split, on a bit by bit basis, into a pair of secret-sharing bits, and the secret-sharing bits of each pair of secret-sharing bits are separated into separate streams of secret-sharing bits. In this manner, one secret-sharing bit of each pair of secret-sharing bits may be placed in one stream of secret-sharing bits and the other secret-sharing bit of each pair may be placed in another stream of secret-sharing bits different from the one stream of secret-sharing bits. Confidentiality of the original input stream may be protected in the event one but not both streams of secret-sharing bits is obtained by unauthorized personnel.

Abstract: Provided are a computer program product, system, and method for determining whether to extend a drain time to copy data blocks from a first storage to a second storage. A data structure is generated indicating data blocks in the first storage to copy to the second storage. A drain operation is initiated to copy the data blocks indicated in the first storage to the second storage for a drain time period. Write requests to the data blocks indicated in the data structure are queued during the drain time period, wherein the queued write requests are not completed while queued. Metric information based on the writes that occur to data blocks in the first storage are gathered during the drain time period; and in response to expiration of the drain time period, a determination is made from the gathered metric information of whether to continue the drain operation or terminate the drain operation.

Abstract: Provided are a computer program product, system, and method for determining whether to extend a drain time to copy data blocks from a first storage to a second storage. A data structure indicates data blocks in the first storage to copy to the second storage. A drain operation copies the data blocks indicated in the first storage to the second storage for a drain time period. Write requests to the data blocks indicated in the data structure are queued during the drain time period, wherein the queued write requests are not completed while queued. Metric information based on the writes that occur to data blocks in the first storage are gathered during the drain time period; and in response to expiration of the drain time period, a determination is made from the gathered metric information of whether to continue the drain operation or terminate the drain operation.

Abstract: In one embodiment, pursuant to migrating the data from the first to the second storage medium, the data is allocated to the second storage medium while retaining an allocation of the data in the first storage medium. If the data is migrated from the second storage medium back to the first storage medium, the data is pointed to the allocation of the data in the first storage medium to alleviate data movement from the second storage medium to the first storage medium. If the allocation of the data in the first storage medium is determined to be needed for other data, the allocation of the data in the first storage medium is freed.

Abstract: In one embodiment, pursuant to migrating the data from the first to the second storage medium, the data is allocated to the second storage medium while retaining an allocation of the data in the first storage medium. If the data is migrated from the second storage medium back to the first storage medium, the data is pointed to the allocation of the data in the first storage medium to alleviate data movement from the second storage medium to the first storage medium. If the allocation of the data in the first storage medium is determined to be needed for other data, the allocation of the data in the first storage medium is freed.

Abstract: A read/write ratio for each of a plurality of data segments classified in a hot category as hot data segments is determined. Each of the plurality of hot data segments is ordered by the read/write ratio in a descending order. Each of a plurality of available SSD devices is ordered by a remaining life expectancy in an ascending order. Those of the plurality of hot data segments are matched with those of the plurality of hot data segments with those of the plurality of available SSD devices such that a hot data segment having a higher read/write ratio is provided to an SSD device having a smaller remaining life expectancy than another hot data segment having a lower read/write ratio.

Abstract: A read/write ratio for each of a plurality of data segments classified in a hot category as hot data segments is determined. Each of the plurality of hot data segments is ordered by the read/write ratio in a descending order. Each of a plurality of available SSD devices is ordered by a remaining life expectancy in an ascending order. Those of the plurality of hot data segments are matched with those of the plurality of hot data segments with those of the plurality of available SSD devices such that a hot data segment having a higher read/write ratio is provided to an SSD device having a smaller remaining life expectancy than another hot data segment having a lower read/write ratio.

Abstract: In one embodiment, a system, includes logic for creating a snapshot of first data stored on a source storage system, wherein the snapshot is a logical copy of the first data stored on the source storage system with respect to data content and data structure; logic for copying the snapshot to a target storage system; logic for copying the first data represented by the snapshot from the source storage system to the target storage system; logic for detecting one or more write operations affecting data on the source storage system; logic for detecting one or more collisions affecting the first data on the source storage system, logic for setting a consistency group interval; and logic for altering the consistency group interval to minimise collisions affecting data on the source storage system. Other systems and computer program products for dynamic consistency group formation are also described.

Abstract: A method for dynamic consistency group formation, in one embodiment, includes creating a snapshot of first data stored on a source storage system with respect to data content and data structure, copying the snapshot to a target storage system, detecting one or more write operations affecting data on the source storage system while copying the first data, detecting one or more collisions affecting the first data on the source storage system, wherein a collision occurs whenever the write operations affect the first data prior to the first data being written, setting a consistency group interval which represents an interval duration between successive snapshot create-and-copy events, and altering the consistency group interval to minimize collisions affecting data on at least one of the storage systems. Other methods for dynamic consistency group formation are also described.

Abstract: A method for more effectively distributing the I/O workload in a data replication system is disclosed herein. In selected embodiments, such a method may include generating an I/O request and identifying a storage resource group associated with the I/O request. In the event the I/O request is associated with a first storage resource group, the I/O request may be directed to a first storage device and a copy of the I/O request may be mirrored from the first storage device to a second storage device. Alternatively, in the event the I/O request is associated with a second storage resource group, the I/O request may be directed to a second storage device and a copy of the I/O request may be mirrored from the second storage device to the first storage device.

Abstract: Provided are a computer program product, system, and method for determining whether to extend a drain time to copy data blocks from a first storage to a second storage. A data structure indicates data blocks in the first storage to copy to the second storage. A drain operation copies the data blocks indicated in the first storage to the second storage for a drain time period. Write requests to the data blocks indicated in the data structure are queued during the drain time period, wherein the queued write requests are not completed while queued. Metric information based on the writes that occur to data blocks in the first storage are gathered during the drain time period; and in response to expiration of the drain time period, a determination is made from the gathered metric information of whether to continue the drain operation or terminate the drain operation.

Abstract: A method for dynamic consistency group formation, in one embodiment, includes creating a snapshot of first data stored on a source storage system with respect to data content and data structure, copying the snapshot to a target storage system, detecting one or more write operations affecting data on the source storage system while copying the first data, detecting one or more collisions affecting the first data on the source storage system, wherein a collision occurs whenever the write operations affect the first data prior to the first data being written, setting a consistency group interval which represents an interval duration between successive snapshot create-and-copy events, and altering the consistency group interval to minimize collisions affecting data on at least one of the storage systems. Other methods for dynamic consistency group formation are also described.