Abstract: Providing TCP/IP control commands to a storage system includes intercepting TCP/IP data provided on a TCP/IP network, determining if the TCP/IP data corresponds to a control command directed to the storage system, and converting the TCP/IP data to a Fibre Channel control command that is forwarded to the storage system if the TCP/IP data is a control command directed to the storage system. A host may intercept the TCP/IP data. The host may be coupled to the storage system. The storage system may have only Fibre Channel connectivity. A PC having only TCP/IP connectivity may provide the control commands via the TCP/IP network. At least two hosts may be coupled to the TCP/IP network. Software on one of the hosts may provide the control commands for the storage system. The storage system may be coupled to an other one of the hosts.

Abstract: Copying data from a source storage system to a target storage system includes resetting a write tracker on the source storage system to track writes to the source storage system by one or more host computing systems, copying data from the source storage system to the target storage system after resetting the write tracker, suspending writes to the source storage system after copying the data, and copying data portions of the source storage system to the target storage system that are indicated as being written by the write tracker after suspending writes to the source storage system. Applications that write data to the source storage system may be quiesced in connection with suspending writes to the source storage system. Data portions may be repeatedly copied from the source storage system to the target storage system until an end condition is reached.

Abstract: Transitioning from using a donor four site replication system to using a target four site replication system includes initiating synchronization between a first local storage system of the donor four site replication system that receives I/O from a host with an alternative first local storage system of the target four site replication system, the host switching to automatically fail over to a synchronous storage system of the target four site replication system that receives synchronous data from the alternative first local storage system following synchronizing the first local storage system with the alternative first local storage system, and the host switching to perform I/O operations with the alternative first local storage system following switching to automatically fail over to the synchronous storage system. The host may run the z/OS operating system. The host may automatically fail over to a storage system by switching subchannel sets.

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: 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: 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: 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: Creating point-in-time versions of files for applications at a storage system includes maintaining at the storage system a data structure correlating each of a plurality of applications with files for each of the applications and correlating each of the files with portions of the data storage system, using the data structure to determine specific files for a particular one of the applications for which a point-in-time version is being created, using the data structure to determine specific portions of the storage system corresponding to the specific files, suspending writes to the specific portions, completing previous writes to the specific portions following suspending writes, and performing a snapshot of the specific files following completing previous writes. The portions of the data storage may be extents. A host may provide information to the storage system to correlate applications with files and to correlate files with portions of the data storage system.

Abstract: Transforming data that is provided by a first instance of an application that uses application-instance specific data includes determining if a component of the data is an application-instance specific component and, if the component is an application-instance specific component, transforming the component either at a storage system containing the data or as the component is being accessed by a second instance of the application, different from the first instance. Transforming the component at a storage system containing the data may be performed independently of any accesses of the data. Transforming the component at a storage system containing the data may be performed by the storage system. The first instance of the application may run on a first host and the second instance of the application may run on a second host different from the first host. The first and second instances of the application may run on a same host.

Abstract: Accessing additional storage space of a storage system includes reading a physical data fragment that is an incremental subset of a physical storage unit of the storage system, accessing metadata corresponding to logical blocks stored on the physical data fragment to determine a sidebar storage portion of the physical data fragment that is unused by the logical blocks, and accessing data of the sidebar storage portion. Accessing data of the sidebar storage portion may include providing data from the sidebar storage portion to a calling process. Accessing data of the sidebar storage portion may include modifying a portion of data from the physical data fragment and writing the physical data fragment back to the physical storage device. The physical data fragment may be locked prior to reading the physical data fragment and the physical data fragment may be unlocked after writing the physical data fragment.

Abstract: Directly writing snapshot data for a volume on a storage system to an external storage includes receiving a write of new data to a portion of the storage system, forming encapsulated data by encapsulating either the new data or data at the portion of the storage system in a format that is native to the storage system, and directly writing the encapsulated data to the external storage. The external storage may be cloud storage or may be a tape emulation unit. The data at the portion of the storage system may be encapsulated prior to writing the new data to the storage system. The new data may be encapsulated. Prior to receiving a write of the new data, a full backup may be performed from the storage system to the external storage. The encapsulated data may provide an incremental backup for the full backup.

Abstract: Transitioning from using a donor four site replication system to using a target four site replication system includes initiating synchronization between a first local storage system of the donor four site replication system that receives I/O from a host with an alternative first local storage system of the target four site replication system, the host switching to automatically fail over to a synchronous storage system of the target four site replication system that receives synchronous data from the alternative first local storage system following synchronizing the first local storage system with the alternative first local storage system, and the host switching to perform I/O operations with the alternative first local storage system following switching to automatically fail over to the synchronous storage system. The host may run the z/OS operating system. The host may automatically fail over to a storage system by switching subchannel sets.

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: Writing new data to a tape volume of a tape emulation unit includes determining if the new data is an update to data that was previously written, writing the new data to a new section of the tape emulation unit in response to the new data not updating data that was previously written, deleting the data that was previously written and writing the new data to a new section in response to the new data updating data that was previously written, the new data being larger than the data that was previously written, and the underlying file system not supporting variable size records/blocks, and overwriting the data that was previously written in response to the new data updating data that was previously written and either the new data not being larger than the data that was previously written or the underlying file system supporting variable size records/blocks.

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: Transferring data between a first storage device coupled to a host computing system and a second storage device coupled to the first storage device includes the first storage device receiving a command from the host computing system, the first storage device determining if the command is an out-of-band (OOB) storage command, and, if the command is an OOB storage command, the first storage device sending a command to the second storage device to cause data to be transferred directly between the first storage device and the second storage device independent of the host computing system. Transferring data between a first storage device coupled to a host computing system and a second storage device coupled to the first storage device may also include the first storage device emulating a host computing system in connection with communicating with the second storage device. The second storage device may be a tape emulation unit.

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: Using an alternative communication protocol between a first system and a second system that are otherwise configured to communicate using a FICON protocol includes the first system determining if the alternative communication protocol is handled by the second system, the first system providing encapsulated data by encapsulating FICON data if the alternative communication protocol is handled at the second system, and the first system transmitting the encapsulated data directly to the second system using the alternative communication protocol if the alternative communication protocol is handled at the second system. The alternative communication protocol may be TCP/IP. At least one of the systems is a host computing system, an array storage system, and/or a tape emulation system. At least one of the systems may be a simulation of a host computing system, an array storage system, and/or a tape emulation system.

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.