Abstract: Extending snapshot retention for a storage system includes creating a plurality of entries, each of the entries corresponding to snapshot data on the storage system and containing data that was written in connection with the snapshot and containing a map indicating which portions of the storage system were modified and includes transferring the entries to an external storage that is separate from the storage system. The map may be an SDDF map that indicates tracks of data that were modified. The external storage may be a cloud storage. Each of the entries may be created prior to deleting data for a corresponding snapshot on the storage system. The entries may be transferred directly from the storage system to the external storage. Extending snapshot retention for a storage system may also include periodically writing a full version of data from the storage device to the external storage.

Abstract: Maintaining versions of data from a storage system includes detecting that a snapshot of the data has been performed at the storage device, transferring a previous version of the data to a cloud storage, and prohibiting deletion of the snapshot until the previous version of the data has been completely transferred to the cloud storage. The data may be a volume on the storage system. The cloud storage may be public cloud storage or part of a private network. The cloud storage may be accessible from any location via the World Wide Web. A connection between the storage device and the cloud storage may be provided by the Internet, a TCP/IP network, a dedicated connection, or a FICON connection. The snapshot may store a log entry in a log device corresponding to a particular point-in-time version of the data prior to data being written to the storage device.

Abstract: Changing operational backup parameters on a storage system includes a first actor generating a request to change operational backup parameters, providing the request from the first actor to a second actor, the second actor authorizing the request, and modifying the operational backup parameters in response to the second actor authorizing the request. The first actor may be assigned a role that allows the first actor to generate the request to change operational backup parameters of the storage system and the second actor may be assigned a role that allows the second actor to authorize the request to change operational backup parameters of the storage system. The request may include a time window provided by the first actor. Authorizing a request to change operational backup parameters of the storage system may create a token and an authorization key. The token may be indicative of the request provided by the first actor.

Abstract: Obtaining a consistent set of snapshots of a group of storage volumes includes obtaining a plurality of snapshots, each of the snapshots being for one of the volumes, determining if there are any specific write operations to at least one volume that occurred after obtaining a first one of the snapshots and before obtaining a last of the snapshots, if there are any specific write operations, discarding the plurality of snapshots, and, if there are no specific write operations, designating the plurality of snapshots as the consistent set of snapshots. Obtaining a consistent set of snapshots may include repeatedly obtaining a plurality of snapshots and determining if there are specific write operations until either a particular condition is met or there are no specific write operations determined. The particular condition may be exceeding a predetermined number of iterations or a predetermined time limit.

Abstract: Maintaining a timestamp indicating when data transferred to a remote storage system was written by a host at a local storage system includes writing a timestamp file at the local storage system, the timestamp file being part of a first chunk of data corresponding to current writes to the local storage system by the host, providing a second chunk at the local storage system, the second chunk being different from the first chunk and corresponding to writes by the host that were begun prior to beginning any of the writes for the first chunk, and transferring the writes for the second chunk to the remote storage system. Each chunk may be assigned a sequence number. The remote storage system may acknowledge receipt after receiving all data for the second chunk. The second chunk may be written to the remote storage system after receiving all data for the second chunk.

Abstract: Extending snapshot retention for a storage system includes creating a plurality of entries, each of the entries corresponding to snapshot data on the storage system and containing data that was written in connection with the snapshot and containing a map indicating which portions of the storage system were modified and includes transferring the entries to an external storage that is separate from the storage system. The map may be an SDDF map that indicates tracks of data that were modified. The external storage may be a cloud storage. Each of the entries may be created prior to deleting data for a corresponding snapshot on the storage system. The entries may be transferred directly from the storage system to the external storage. Extending snapshot retention for a storage system may also include periodically writing a full version of data from the storage device to the external storage.

Abstract: Backing up logical data from a storage system to a backup system includes accessing data on the storage system corresponding to logical file structures of data stored on the storage system, using machine learning to ascertain file access patterns and frequency of file backups, determining backup data based on the logical file structure of data stored on the storage system and the file access patterns and frequency of file backups, and directly transferring data corresponding the backup data from the storage system to the backup system. The logical file structures may be provided by file metadata. The file metadata may include at least one of: a VTOC (volume table of contents), an IXVTOC (indexed VTOC), VSAM (virtual storage access method) information, a VVDS (VSAM volume data set), file attributes, and/or catalog data. The file attributes may include management class information for each of the files.

Abstract: Accessing data using a first storage device and a second storage device that is a synchronous mirror of the first storage device includes determining if the first and second storage devices support alternative mirroring that bypasses having the first storage device write data to the second storage device and choosing to write data to the first storage device only or both the first and second storage device based on criteria that includes metrics relating to timing, an identity of a calling process or application, a size of an I/O operation, an identity of a destination volume, a time of day, a particular host id, a particular application or set of applications, and/or particular datasets, extents, tracks, records/blocks. A single I/O operation may be bifurcated to provide a portion of the I/O operation to only the first storage device or to both the first storage device and the second storage device.

Abstract: Creating snapshot data sets for a plurality of logical devices of a storage system includes marking an initial set of the logical devices for a snapshot in response to each of the initial set of logical devices having been modified since obtaining a previous snapshot data set, suspending I/O operations, marking an additional set of the logical devices for a snapshot in response to each of the additional set of logical devices having been modified prior to suspending I/O, performing a snapshot of the logical devices in the initial set of logical devices and in the additional set of logical devices, and resuming I/O operations. Pointers to snapshots for the snapshot data set may be placed in a table that includes a plurality of entries for a plurality of snapshot data sets. None of the additional set of logical devices may be part of the initial set of logical devices.

Abstract: Changing operational backup parameters on a storage system includes a first actor generating a request to change operational backup parameters, providing the request from the first actor to a second actor, the second actor authorizing the request, and modifying the operational backup parameters in response to the second actor authorizing the request. The first actor may be assigned a role that allows the first actor to generate the request to change operational backup parameters of the storage system and the second actor may be assigned a role that allows the second actor to authorize the request to change operational backup parameters of the storage system. The request may include a time window provided by the first actor. Authorizing a request to change operational backup parameters of the storage system may create a token and an authorization key. The token may be indicative of the request provided by the first actor.

Abstract: Maintaining versions of data from a storage system includes detecting that a snapshot of the data has been performed at the storage device, transferring a previous version of the data to a cloud storage, and prohibiting deletion of the snapshot until the previous version of the data has been completely transferred to the cloud storage. The data may be a volume on the storage system. The cloud storage may be public cloud storage or part of a private network. The cloud storage may be accessible from any location via the World Wide Web. A connection between the storage device and the cloud storage may be provided by the Internet, a TCP/IP network, a dedicated connection, or a FICON connection. The snapshot may store a log entry in a log device corresponding to a particular point-in-time version of the data prior to data being written to the storage device.

Abstract: Data replication techniques may include receiving, at a first data storage system, a write operation that writes first data to a source logical device, wherein the source logical device is configured for remote replication using a first replication technology and also configured for remote replication using a second replication technology different from the first replication technology. The first technology may be a first vendor and the second replication may be from a second vendor different from the first vendor. Responsive to receiving the write operation on the first data storage system, processing may be performed comprising: replicating the write operation and writing the first data to a first target logical device on a second data storage system using the first replication technology; and replicating the write operation and writing the first data to a second target logical device on a third data storage system using the second replication technology.

Abstract: Detecting data corruption in a storage system includes examining portions of the data for encryption anomalies and providing an indication in response to detecting an encryption anomaly. The encryption anomalies may be based on entropy of the data. The entropy of the data may vary based on an inherent nature of the data. One of the portions of data may be deemed to be encrypted in response to an entropy value exceeding a predetermined threshold. The predetermined threshold may be based on prior data accesses. The predetermined threshold may be determined using machine learning. Portions of the data may be examined for encryption anomalies during data accesses. Data accesses may be suspended in response to detecting an encryption anomaly. Encryption anomalies may include data that is flagged to be encrypted not being detected as being encrypted and/or data that is flagged to not be encrypted being detected as being encrypted.

Abstract: Migrating data from a first storage system to a second storage system includes transferring the data from the first storage system to a cloud storage, transferring the data from the cloud storage to the second storage system, quiescing the first storage system prior to transferring remaining data from the first storage system to the cloud storage, and transferring remaining data from the cloud storage to the second storage system to complete migration of the data. The cloud storage may be accessible only through a private network or via the World Wide Web. Quiescing the first storage system may include the first storage system rejecting write operations or may include one or more external systems coupled to the first storage system foregoing write operations. Snapshots may be performed at the first storage system in response to commands provided by a host coupled to the first storage system.

Abstract: Migrating data from a first storage device to a second storage device includes causing all data of the first storage device to be copied from the first storage device to the second storage device and causing the host computer to transition from performing I/O operations with the first storage device to performing I/O operations with the second storage device by modifying metadata used for I/O operations to change a mapping of logical devices to physical devices only after causing all data of the first storage device to be copied from the first storage device to the second storage device. Migrating data from the first storage device to the second storage device is independent of any I/O operations by the host. A data write operation from the host is acknowledged only after the data has been successfully written to both the first storage device and the second storage device.

Abstract: Detecting data corruption in a storage device includes periodically examining portions of the data for unusual access patterns and/or unusual data manipulation and providing an indication in response to detecting unusual access patterns and/or unusual data manipulation. The unusual access patterns may be determined based on a number of data reads per unit time and/or a number of data writes per unit time. The number of data reads per unit time and the number of data writes per unit time may be determined using a counter of a flag that is set each time a data portion is accessed. Thresholds that are based on prior data accesses may be used to determine unusual access patterns. A user may set different thresholds for different portions of the data. A cyclic threshold may be used for cyclic access data and a level threshold may be used for non-cyclic data.

Abstract: Migrating data from a first storage device to a second storage device includes causing all data of the first storage device to be copied from the first storage device to the second storage device and causing the host computer to transition from performing I/O operations with the first storage device to performing I/O operations with the second storage device by modifying metadata used for I/O operations to change a mapping of logical devices to physical devices only after causing all data of the first storage device to be copied from the first storage device to the second storage device. Migrating data from the first storage device to the second storage device is independent of any I/O operations by the host. A data write operation from the host is acknowledged only after the data has been successfully written to both the first storage device and the second storage device.

Abstract: Accessing a portion of data that was previously migrated to a cloud service includes initiating a recall of the data from the cloud service in response to the data residing entirely on the cloud service, determining if the portion of the data is stored on the storage device, retrieving cloud objects from the cloud service corresponding to the portion of the data in response to the portion of the data being unavailable on the storage device, and accessing the portion of the data on the storage device while cloud objects corresponding to other portions of the data are being transferred from the cloud service to the storage device. The host may receive a migrated status indicator in response to the data existing entirely on the cloud service. Initiating the recall may include modifying metadata to indicate that the data is available for access by the host.

Abstract: Restoring data from a storage device to a cloud service includes initializing each of a plurality of flags for each of portions of the data when the data is initially recalled from the cloud service to the storage device, the flags indicating whether a corresponding portion of the data has been modified while being stored on the storage device, modifying a particular one of the flags in response to a corresponding one of the portions being modified, transferring only portions of the data having corresponding flags that have been modified to migrate, and merging the portions of the data with remaining data at the cloud service. Data that is recalled from the cloud service to the storage device may be maintained on the cloud service. The portions of data that are transferred from the storage device to the cloud service may overwrite data maintained at the cloud service.

Abstract: A system and method for data replication is provided. A host synchronously replicates data between a first local storage device and a second local storage device, the first local storage device and the second local storage device being coupled to the host. Data is then asynchronously replicated from the first local storage device and the second local storage device to at least one remote storage device. In an embodiment, each of the local storage devices may asynchronously replicate data to remote storage devices located at separate sites to provide four site data replication processing. The system described herein provides for advantageous and efficient swapping of control between hosts and storage devices located in different regions in response to disasters and/or other events affecting data storage in a particular region.