Abstract: Systems and techniques are provided for incremental Continuous Data Protection (iCDP) as a process to secure frequent, and space efficient, versions of consistent point-in-time images of a group of volumes using snapshot technology. The system provides for automation to create and manage frequent snapshots of defined groups of volumes. The incremental approach of the system described herein provides a convenient way to roll back to prior point-in-time versions to investigate data damage due to processing errors or other forms of corruption. Log space in log devices may be reclaimed in connection with managing recovery and roll back capabilities of the system to desired data versions for purposes of data protection. Point in time versions of a source device may be accessed through the source device. The particular point in time version accessed in servicing an I/O may be determined in accordance with one or more criteria.

Abstract: Releasing a data set at a source device in connection with migrating data from the source device to a target device includes mapping application address space to address space containing metadata for the target device and providing additional local metadata therefor, replacing within the application the address of metadata for the source device with the address of metadata for the target device, setting a diversion flag that is part of the additional local metadata, where the diversion flag indicates a remapping of extent, and closing and unallocating the data set at the source device. Releasing a data set at a source device in connection with migrating data from the source device to a target device may also include determining if an application uses standard I/O operations. The metadata may include UCB data.

Abstract: A system for injecting I/O faults into a closed system, for example, the injection of link level I/O faults, involves the use of a simulated computing environment. In an embodiment, the system provides for fault injection using an emulated IBM System z environment and including the use of FICON and/or other suitable communication channel protocols. The emulated System z environment may include a simulated z/OS and/or emulated System z hardware and software components.

Abstract: Releasing a data set at a source device in connection with migrating data from the source device to a target device includes mapping application address space to address space containing metadata for the target device and providing additional local metadata therefor, replacing within the application the address of metadata for the source device with the address of metadata for the target device, setting a diversion flag that is part of the additional local metadata, where the diversion flag indicates a remapping of extent, and closing and unallocating the data set at the source device. Releasing a data set at a source device in connection with migrating data from the source device to a target device may also include determining if an application uses standard I/O operations. The metadata may include UCB data.

Abstract: Transferring storage device functionality includes providing a device coupled to the storage device, where the device is separate from the storage device, having the device handle I/O requests between an application and the storage device, and, in response to the application issuing an I/O request, having the device determine if the request corresponds to functionality being transferred and, if so, having the device provide the functionality. The device may be a host computer. The application may run on the host computer. A driver on the host computer may provide the functionality. The functionality may include read only functionality, data compression, data encryption, mirroring, and/or status reporting.

Abstract: A reclaim system provides for marking each track that is intended to be reclaimed in one or more storage devices and detecting and reclaiming such tracks. The reclaim system may include a feature and/or utility that may be used to mark, detect and return tracks to a free track pool of a virtual provisioning storage system in connection with the use of one or more thin Count Key Data (CKD) devices. Reclaim processing may include identifying tracks to be reclaimed, marking mark the tracks to be reclaimed, detecting tracks that have been marked to be reclaimed, and performing a reclaim task to return the marked and detected tracks to the free track pool, thereby reclaiming the tracks.

Abstract: Maintaining tape emulation consistency includes writing additional tape data to a first local storage device at a local site, writing tape emulation data to a second local storage device at the local site, where the second local storage device is different from the first local storage device, and maintaining consistency of the first and second local storage devices in connection with transferring data to a remote site. Maintaining consistency of the first and second local storage devices may include initiating a cycle switch that causes a concurrent cycle change from a first cycle to a second cycle for the first and second local storage devices. Additional tape data and tape emulation data written before a first time is associated with a first cycle. Additional tape data and tape emulation data written after the first time and before a second time is associated with a second cycle.

Abstract: Described are techniques for providing access to storage devices. An I/O request directed to a storage device is sent over a network connection from a first computer system to a second computer system. The second computer system includes a simulated computing environment simulating aspects of the first computer system. The I/O request is received at the second computer system. The data storage system is connected to the second computer system over a first connection operating in accordance with a first protocol thereby providing the second computer system access to the storage device of the data storage system. The simulated computing environment of the second computer system may, for example, include emulation capabilities in accordance with the first protocol thereby allowing the second computer system to issue the first I/O request to the first storage device on behalf of the first computer system.

Abstract: Transferring storage device functionality includes providing a device coupled to the storage device, where the device is separate from the storage device, having the device handle I/O requests between an application and the storage device, and, in response to the application issuing an I/O request, having the device determine if the request corresponds to functionality being transferred and, if so, having the device provide the functionality. The device may be a host computer. The application may run on the host computer. A driver on the host computer may provide the functionality. The functionality may include read only functionality, data compression, data encryption, mirroring, and/or status reporting.

Abstract: Maintaining continuous availability of tape data includes providing a first storage space that contains the tape data, where metadata for the tape data points to the first storage space, creating a data mirroring relationship between the first storage space and a second, separate, storage space, where tape data written to the first storage space is copied to the second storage space, and adjusting the metadata for the tape data to reference the second storage space in response to the first storage space becoming inaccessible. Maintaining continuous availability of tape data may also include suspending access to the tape data prior to adjusting the metadata. Maintaining continuous availability of tape data may also include resuming access to the tape data after adjusting the metadata.

Abstract: Maintaining tape emulation consistency includes writing additional tape data to a first local storage device at a local site, writing tape emulation data to a second local storage device at the local site, where the second local storage device is different from the first local storage device, and maintaining consistency of the first and second local storage devices in connection with transferring data to a remote site. Maintaining consistency of the first and second local storage devices may include initiating a cycle switch that causes a concurrent cycle change from a first cycle to a second cycle for the first and second local storage devices. Additional tape data and tape emulation data written before a first time is associated with a first cycle. Additional tape data and tape emulation data written after the first time and before a second time is associated with a second cycle.

Abstract: Described are techniques used in defining and maintaining group data used by multiple host systems. Group data is stored in a distributed fashion on one or more data storage systems. If a device of a data storage system belongs to a group, group data for that group is stored on that data storage system. Group data changes made by one host are communicated to the other hosts by accessing a common data area on each data storage system using a daemon executing on each host. Remotely mirrored groups may be defined on a remote data storage system. A remote mirror of a group includes group data modified in accordance with a point of view of the remote data storage system and a remote host.

Abstract: Managing data on a storage device includes intercepting unencrypted data to be stored on the storage device, where intercepting unencrypted data is transparent to an application storing the data on the storage device and encrypting the data prior to storage on the storage device. The storage device may include a tape drive and/or a disk drive. Managing data on a storage device may also include migrating data from a first storage location to a second storage location. The first storage location may be the same as the second storage location or the first storage location may be different from the second storage location. The unencrypted data may be intercepted during migration. Managing data on a storage device may also include decrypting data read from the storage device.

Abstract: Non-disruptive modification of data in-place includes generating a copy of source data to a holding area. Data modification, such as encryption and/or other transformation process, may be performed on the source data in the source area while I/O operations of applications needing access to the source data is diverted to the data copy in the holding area. Updates to the data copy in the holding area from the continued I/O operations are tracked and the data updates are modified and transferred to the source area. Following successful modification of the source data, the I/O operations of the applications are re-directed back to the source area having the newly modified source data. The holding area may then be freed for subsequent use.

Abstract: A method and apparatus for migrating one or more data sets each having one or more extents from one or more source logical devices to one or more target logical devices concurrently with interaction between the application and the data being migrated. A background operation copies each extent from the source logical device to the target logical device in a copy state. When a certain level of data has been copied, the extent is locked to assure synchronization of the data in the target logical device to the corresponding data in the source logical device. The status is changed to a mirrored state. When the extents for a data set in a source logical device or in a group of data sets have been mirrored, all the extents are changed to a diverted state. I/O requests to the diverted extents thereafter are intercepted and processed according to whether they access an extent that is in the copy, mirrored, or diverted state.

Abstract: Determining when to migrate a data set includes providing performance criteria for the data set, measuring performance of the data set to provide a measured performance of the data set, and, if the measured performance indicates that the data set is not performing according to the performance criteria, choosing a new location for migrating the data set and migrating the data set to the new location. Migrating the data set may include moving the data set to a new location irrespective of whether other applications are accessing the data set. Choosing a new location may include analyzing each of a plurality of locations to determine if a projected performance thereof is according to the performance criteria. Determining when to migrate a data set may include adjusting the performance criteria after the data set has been made operational.

Abstract: A host computer system (host) includes an application that generates I/O commands for a first type of point-in-time (PIT) copy operation, and an I/O subsystem coupled to a data storage system capable of performing a second type of PIT copy operation. The host processes the I/O commands as part of an emulation of the first type of PIT copy operation, including determining whether the I/O commands require modification for the emulation, and if so whether they are of a back-end type or an out-of-band type. The I/O commands that do not require modification are processed without modification via the I/O subsystem. For the back-end I/O commands, (i) an intercept condition is set, (ii) the I/O commands are processed via the I/O subsystem, and (iii) upon completion with the intercept condition set, the results are modified so as to indicate to the application that the first type of PIT copy operation can be performed on the storage volumes.

Abstract: Providing a mechanism for performing special processing in connection with application I/O operations for a device includes mapping application address space to address space containing metadata for the device and providing additional local metadata therefor and providing an eyecatcher in the additional local metadata. Providing a mechanism for performing special processing in connection with application I/O operations for a device may also include determining if the application uses standard I/O operations. The metadata may include UCB data. The additional local metadata may be provided immediately following the application address space mapped to the address space containing metadata.

Abstract: Managing data on a storage device includes intercepting unencrypted data to be stored on the storage device, where intercepting unencrypted data is transparent to an application storing the data on the storage device and encrypting the data prior to storage on the storage device. The storage device may include a tape drive and/or a disk drive. Managing data on a storage device may also include migrating data from a first storage location to a second storage location. The first storage location may be the same as the second storage location or the first storage location may be different from the second storage location. The unencrypted data may be intercepted during migration. Managing data on a storage device may also include decrypting data read from the storage device.

Abstract: A method and apparatus for migrating one or more data sets each having one or more extents from one or more source logical devices to one or more target logical devices concurrently with interaction between the application and the data being migrated. A background operation copies each extent from the source logical device to the target logical device in a copy state. When a certain level of data has been copied, the extent is locked to assure synchronization of the data in the target logical device to the corresponding data in the source logical device. The status is changed to a mirrored state. When the extents for a data set in a source logical device or in a group of data sets have been mirrored, all the extents are changed to a diverted state. I/O requests to the diverted extents thereafter are intercepted and processed according to whether they access an extent that is in the copy, mirrored, or diverted state.