Abstract: An apparatus for real-time performance management of a virtualized storage system operable in a network having managed physical storage and virtual storage presented by an in-band virtualization controller comprises: a monitoring component operable in communication with the network for acquiring performance data from the managed physical storage and the virtual storage; and a cache controller component responsive to the monitoring component for adjusting cache parameters for the virtual storage. The apparatus may further comprise a queue controller component responsive to the monitoring component for adjusting queue parameters for the managed physical storage. The monitoring component, the cache controller component and the queue controller component may be configured to operate periodically during operation of the virtualized storage system.

Abstract: A backup control apparatus for periodic data backup, in a virtualized storage system having a point-in-time copy function operable to copy first data into a cascade, comprises a storage targeting component for selecting a target virtual disk for one of a full copy or an incremental copy of the first data; a periodic backup component for triggering a periodic point-in-time copy of the first data to a virtual disk in the cascade; a testing component for testing a status of the full copy, the incremental copy and the periodic point-in-time copy; and a cascade splitting component responsive to the status for splitting the cascade to remove a dependency relationship of at least one of the full copy, the incremental copy and the periodic point-in-time copy on the first data.

Abstract: A targeting storage component selects a target virtual disk for one of a full copy or an incremental copy of first data. A periodic backup component triggers a periodic point-in-time copy of the first data to a virtual disk in the cascade. A testing component tests a status of the full copy, the incremental copy and the periodic point-in-time copy. Responsive to the status, a cascade splitting component splits the cascade to remove a dependency relationship of at least one of the fully copy, the incremental copy and the periodic point-in-time copy on the first data.

Abstract: Provided are techniques for maintaining instant virtual copies. A request to perform an instant virtual copy operation to create an instant virtual copy from a first volume to a new volume is received. It is determined that the first volume has not been modified since a last instant virtual copy operation has been performed. It is determined whether an intermediate volume and an intermediate map have already been created. In response to determining that the intermediate volume and the intermediate map have not already been created, the intermediate volume and the intermediate map are created, the intermediate volume is made dependent on the first volume in a dependency chain based on the intermediate map, and the new volume is made dependent on the intermediate volume in the dependency chain.

Abstract: Provided are techniques for maintaining instant virtual copies. A request to perform an instant virtual copy operation to create an instant virtual copy from a first volume to a new volume is received. It is determined that the first volume has not been modified since a last instant virtual copy operation has been performed. It is determined whether an intermediate volume and an intermediate map have already been created. In response to determining that the intermediate volume and the intermediate map have not already been created, the intermediate volume and the intermediate map are created, the intermediate volume is made dependent on the first volume in a dependency chain based on the intermediate map, and the new volume is made dependent on the intermediate volume in the dependency chain.

Abstract: There are provided a method, a system and a computer program product for minimizing data transfer latency between redundant storage controllers in a network-based storage controller system that utilizes adaptive data throttling. Each corresponding redundant storage controller calculates average time latency for round trip communications between the corresponding redundant storage controller and the other redundant storage controllers during a fixed monitoring period. The corresponding redundant storage controller, at the end of each fixed monitoring period, compares the average time latency to a fixed latency. The corresponding redundant storage controller selectively throttles data transfer between the corresponding redundant storage controller and a server and data transfer between the corresponding redundant storage controller and a back-end storage, based on the comparison.

Abstract: Provided are a method, computer program product and system for network multi-pathing. Paths to a storage system are through a first network type and a second network type. The first network type has a higher Input/Output (I/O) per second performance characteristic than the second network type. A length is determined from a received I/O request. The I/O request is sent on one of the paths to the storage system through the first network type in response to determining that the length of the I/O request is below a threshold length. The I/O request is sent on one of the paths to the storage system through the second network type in response to determining that the length of the I/O request is above the threshold length.

Abstract: A method for operating a mirrored disk storage system, comprises a detector component operable to detect that a failure has left read stability in doubt, a determiner component for determining a repair characteristic of a pair of mirrored disks, a comparator for comparing the repair characteristic of a first of the pair with the repair characteristic of a second of the pair, and a selector for selecting one of the first or the second of the pair having a preferred repair characteristic to be used as a synchronization source disk. The preferred repair characteristic comprises the characteristic that no repair is required for the one of the first or the second of the pair, or that a least repair time is required for the one of the first or the second of the pair.

Abstract: Provided are a method, system, and a computer program product handling a backup process. An instruction initiates a new backup from a source volume to a target volume using one of a plurality of backup processes. A cascade includes a cascade source volume and at least one cascade target volume, and a write to a storage location in one of the cascade volumes causes a copying of the storage location to be written in the cascade source volume to each of the cascade target volumes in the cascade according to a cascade order in which the at least one cascade target volume and the cascade source volume are linked in the cascade. The cascade is modified to include the target volume of the new backup in response to determining that there is an existing cascade, else a new cascade using the backup process of the new backup is created.

Abstract: A method for optimizing cleaning of maps in FlashCopy cascades includes determining whether a target disk of a map contains data unavailable to a downstream disk from an upstream disk in a FlashCopy cascade and detect whether the downstream disk has a copy of the data. Additionally, the method includes copying the data from the target disk to the downstream disk, if the target disk of the map contains data unavailable to the downstream disk from the upstream disk and the downstream disk does not have the copy of the data. Furthermore, the method includes copying the data from the target disk to the downstream disk, if the target disk of the map does not contain data unavailable to the downstream disk from the upstream disk or the downstream disk does have the copy of the data. Moreover, the method includes removing the map from the FlashCopy cascade.

Abstract: A method for managing storage devices in a storage subsystem having an array of storage devices includes receiving an error message; determining that the error message indicates that at least one storage device in the array of storage devices has failed; collecting an array record comprising storage device characteristics of the failed storage device in response to determining that the error message indicates that at least one storage device has failed; collating a candidate record comprising a plurality of candidate entries; comparing storage device characteristics of the failed storage device of the array record with the storage device characteristics of each of the candidate entries; identifying a first candidate storage device having storage device characteristics that match the storage device characteristics of the failed storage device; and identifying a second candidate storage device having storage device characteristics most similar to the storage device characteristics of the failed storage device.

Abstract: A technique for handling a FlashCopy® process includes receiving a FlashCopy® instruction for a source disk, performing a FlashCopy® point in time copy of the source disk on to a target disk, creating a map specifying the FlashCopy® point in time copy from the source disk to the target disk, creating a primary fdisk for the source disk, if one does not already exist, and creating a primary fdisk for the target disk, if one does not already exist, or, if one does already exist, converting the existing primary fdisk for the target disk into a secondary fdisk, and creating a new primary fdisk for the target disk.

Abstract: A targeting storage component selects a target virtual disk for one of a full copy or an incremental copy of first data. A periodic backup component triggers a periodic point-in-time copy of the first data to a virtual disk in the cascade. A testing component tests a status of the full copy, the incremental copy and the periodic point-in-time copy. Responsive to the status, a cascade splitting component splits the cascade to remove a dependency relationship of at least one of the fully copy, the incremental copy and the periodic point-in-time copy on the first data.

Abstract: A data storage system comprises a controller, a first lower performance storage medium and a second higher performance storage medium. The controller is connected to the storage mediums and is arranged to control Input/Output (IO) access to the storage mediums. In operation, the controller is arranged to store an image on the first storage medium, initiate a copy function from the first storage medium to the second storage medium, direct all IO access for the image to the second storage medium, and periodically age data from the second storage medium to the first storage medium.

Abstract: A method for minimizing latency of data transfer between the redundant storage controllers in a network-based storage controller system that utilizes adaptive data throttling. Each redundant storage controller monitors latency for round trip communications between the redundant controllers by calculating a time required to mirror a write to the other controller and receive a write acknowledge. An average latency for round trip communications between the redundant controllers during a fixed monitoring period is calculated, and at the end of each fixed monitoring period, the average latency is compared to a fixed latency to access the average time latency for mirroring writes is good, acceptable or unacceptable. If the average time latency is good, the one controller reduces or disables throttling for data transfers between the one controller and the server, and between the one controller and back-end storage, increasing a number of this type of data transfer that can be executed in parallel.

Abstract: According to one general embodiment of the present invention, there is provided a computer program product for reducing incidence of errors in connections between a power consumer apparatus operable to draw a load and a power supply apparatus capable of varying the power supplied, the computer program product comprising: a computer readable storage medium having computer readable program code embodied therewith, the computer readable program code comprising: computer readable program code configured to generate at the power consumer apparatus an identifiable pattern in a load to be drawn from a power supply connection to a power supply apparatus; and computer readable program code configured to monitor at the power consumer apparatus for a change in the load corresponding to the pattern, the monitoring being performed across a signal connection to the power supply apparatus; wherein a positive result of the monitoring indicates a correct configuration. Additional embodiments are also presented.

Abstract: A storage control apparatus in cooperation with a plurality of controlled storage apparatus arranged in a cascade of point-in-time copy relationship. The apparatus includes: a rate control component operable to set a desired rate for cleaning a first target one of the plurality of controlled storage apparatus; a comparator component in communication with the rate control component to identify discrepant bits associated with first and second targets; and a copy initiator, responsive to the comparator component to initiate a copy operation responsive to the identified discrepant bits.

Abstract: A method implemented in a computer infrastructure having computer executable code having programming instructions tangibly embodied on a computer readable storage medium. The programming instructions are operable to determine whether a target disk of a map contains data unavailable to a downstream disk from an upstream disk in a FlashCopy cascade and detect whether the downstream disk has a copy of the data. Additionally, the programming instructions are operable to copy the data from the target disk to the downstream disk, if the target disk of the map contains data unavailable to the downstream disk from the upstream disk and the downstream disk does not have the copy of the data. Furthermore, the programming instructions are operable to refrain from copying the data from the target disk to the downstream disk, if the target disk of the map does not contain data unavailable to the downstream disk from the upstream disk or the downstream disk does have the copy of the data.

Abstract: A storage control apparatus cooperable with a plurality of controlled storage apparatus arranged in a cascade of point-in-time copy relationship. The apparatus includes: a rate control component operable to set a desired rate for making clean a first target one of the plurality of controlled storage apparatus; a comparator component responsive to a signal from the rate control component to request and receive metadata from the plurality of controlled storage apparatus and to identify discrepant metadata; and a copy initiator, responsive to the comparator component to identify discrepant metadata and to initiate a copy operation from a first target one of the plurality of controlled storage apparatus to a second target one of the controlled storage apparatus.

Abstract: A controller for use at a node of a clustered computer apparatus includes an exception detection component for detecting an exception raised by a service component at the node; a quiesce component responsive to the exception detection component for quiescing lease-governed activity by the service component prior to termination of a lease; a lease control component responsive to the quiesce component for pre-expiry relinquishing of the lease; and a communication component responsive to the lease control component for communicating the pre-expiry relinquishing of the lease to one or more further nodes of the clustered computer apparatus. The controller may further include a second communication component for receiving a communication indicating the pre-expiry relinquishing of a lease; a second lease control component responsive to the communication to control failure processing; and a second service component to perform a service in place of the service component at the node.