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 data transfer application implemented in a computational device receives a request to copy a plurality of storage volumes that form a consistency group. A determination is made that a first storage volume of the plurality of storage volumes is more likely to be written into than a second storage volume of the plurality of storage volumes, in response to receiving the request to copy the plurality of storage volumes. The first storage volume is copied before copying the second storage volume, in response to determining that the first storage volume is more likely to be written into than the second storage volume.

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 select at least one sample of data; operate a plurality of the data compression engines to compress the selected sample(s); determine the compression ratios of the operated data compression engines with respect to the selected sample(s); and select the data compression engine having the greatest compression ratio with respect to the selected sample(s), to compress the data. Further, the data compression engines may be in tiers from low to high in accordance with expected latency to compress data and to uncompress compressed data; and a data compression engine is selected from a tier that is inverse to the present rate of access.

Abstract: In one aspect of the present description, a data preservation function is provided for preserving a set of data on a source storage device at a point in time, and includes identifying as a function of prior update usage, such as input/output usage, of the data to be preserved, a portion of the data which is more likely to be the subject of updates during at least a portion of the data preservation operation as compared to the remaining portion of the data to be preserved, and copies the identified portion of the data to be preserved to a target storage device. In another aspect, the size of the portion of data to be identified is variable. Other features and aspects may be realized, depending upon the particular application.

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: A method for managing extents in a data storage system includes monitoring usage statistics for an extent residing on one or more powered-up storage devices. In the event the extent has not been accessed for specified period of time (as determined from the usage statistics), the method automatically compresses the extent and migrates the extent to an intermediate repository. Once the amount of data in the intermediate repository reaches a specified level, the method migrates the extent from the intermediate repository to one or more normally powered-down storage devices. If I/O is received for the extent while it resides in the normally powered-down storage devices or the intermediate repository, the method automatically migrates the extent from the normally powered-down storage devices or the intermediate repository to the normally powered-up storage devices. A corresponding apparatus and computer program product are also disclosed.

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: In one aspect of the present description, a data preservation function is provided for preserving a set of data on a source storage device at a point in time, and includes identifying as a function of prior update usage, such as input/output usage, of the data to be preserved, a portion of the data which is more likely to be the subject of updates during at least a portion of the data preservation operation as compared to the remaining portion of the data to be preserved, and copies the identified portion of the data to be preserved to a target storage device. In another aspect, the size of the portion of data to be identified is variable. In one embodiment, the size of the portion of data to be identified is a function of a parameter of the command, such that a user can specify the command parameter which affects the size of the portion of data which is prewritten to the target storage device.

Abstract: A method for managing extents in a data storage system includes monitoring usage statistics for an extent residing on one or more powered-up storage devices. In the event the extent has not been accessed for specified period of time (as determined from the usage statistics), the method automatically compresses the extent and migrates the extent to an intermediate repository. Once the amount of data in the intermediate repository reaches a specified level, the method migrates the extent from the intermediate repository to one or more normally powered-down storage devices. If I/O is received for the extent while it resides in the normally powered-down storage devices or the intermediate repository, the method automatically migrates the extent from the normally powered-down storage devices or the intermediate repository to the normally powered-up storage devices. A corresponding apparatus and computer program product are also disclosed.

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. A corresponding system, apparatus, and computer program product are also disclosed and claimed herein.

Abstract: In one aspect of the present description, a data preservation function is provided for preserving a set of data on a source storage device at a point in time, and includes identifying as a function of prior update usage, such as input/output usage, of the data to be preserved, a portion of the data which is more likely to be the subject of updates during at least a portion of the data preservation operation as compared to the remaining portion of the data to be preserved, and copies the identified portion of the data to be preserved to a target storage device. In another aspect, the size of the portion of data to be identified is variable. Other features and aspects may be realized, depending upon the particular application.

Abstract: A method to perform a version pre-check of a storage controller command, wherein the method extracts a plurality of objects from a storage controller command, and determines, without querying the storage controller, if each object comprising a method or a method parameter is enabled on that storage controller. If each object comprising a method or a method parameter is enabled on the storage controller, the method indicates success for a version pre-check of the storage controller command.

Abstract: In one aspect of the present description, a data preservation function is provided for preserving a set of data on a source storage device at a point in time, and includes identifying as a function of prior update usage, such as input/output usage, of the data to be preserved, a portion of the data which is more likely to be the subject of updates during at least a portion of the data preservation operation as compared to the remaining portion of the data to be preserved, and copies the identified portion of the data to be preserved to a target storage device. In another aspect, the size of the portion of data to be identified is variable. In one embodiment, the size of the portion of data to be identified is a function of a parameter of the command, such that a user can specify the command parameter which affects the size of the portion of data which is prewritten to the target storage device.

Abstract: A data transfer application implemented in a computational device receives a request to copy a plurality of storage volumes that form a consistency group. A determination is made that a first storage volume of the plurality of storage volumes is more likely to be written into than a second storage volume of the plurality of storage volumes, in response to receiving the request to copy the plurality of storage volumes. The first storage volume is copied before copying the second storage volume, in response to determining that the first storage volume is more likely to be written into than the second storage volume.

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 method to perform a version pre-check of a storage controller command, wherein the method extracts a plurality of objects from a storage controller command, and determines, without querying the storage controller, if each object comprising a method or a method parameter is enabled on that storage controller. If each object comprising a method or a method parameter is enabled on the storage controller, the method indicates success for a version pre-check of the storage controller command.

Abstract: Provided are a method, system, and article of manufacture for determining whether data written to source storage locations according to a write order is copied to corresponding target storage locations in the write order. Values are written to indicated source storage locations in a write order. The values written to the source storage locations are copied to corresponding target storage locations. The values at the target storage locations are read and a determination is made from the read values whether the values were written to the target storage locations in the write order.

Abstract: In a shell utility computer program code configured to cause at least one computer processor comprising one host computer system to connect to a second host computer system, and to cause the second host computer system to execute at least one command provided to one host computer system, the computer program code is configured to cause the one host computer system to selectively alter a pre-existing return code for use on shell utility error; and to cause the one host computer system to, in the absence of an alteration to the pre-existing return code, select a pre-existing return code of the shell utility as a default.

Abstract: Provided are a method, system, and article of manufacture for determining whether data written to source storage locations according to a write order is copied to corresponding target storage locations in the write order. Values are written to indicated source storage locations in a write order. The values written to the source storage locations are copied to corresponding target storage locations. The values at the target storage locations are read and a determination is made from the read values whether the values were written to the target storage locations in the write order.