Abstract: A method for verifying the integrity of a communication link is disclosed herein. In selected embodiments, such a method may include detecting, during normal operation of a communication link, a condition indicative of a high failure rate (HFR) on the communication link. The method may further include placing the communication link in an HFR state as a result of the condition. While in HFR state, the method may repeatedly transmit test I/Os over the communication link. The method may then automatically exit HFR state and resume normal operation on the communication link when one or more of the following has occurred: a selected number of test I/Os have been successfully transmitted over the communication link, and a number of test I/Os have been successfully transmitted over the communication link for a selected period of time. A corresponding system, apparatus, and computer program product are also disclosed and claimed herein.

Abstract: A method for verifying the integrity of a communication link is disclosed herein. In selected embodiments, such a method may include detecting, during normal operation of a communication link, a condition indicative of a high failure rate (HFR) on the communication link. The method may further include placing the communication link in an HFR state as a result of the condition. While in HFR state, the method may repeatedly transmit test I/Os over the communication link. The method may then automatically exit HFR state and resume normal operation on the communication link when one or more of the following has occurred: a selected number of test I/Os have been successfully transmitted over the communication link, and a number of test I/Os have been successfully transmitted over the communication link for a selected period of time. A corresponding system, apparatus, and computer program product are also disclosed and claimed herein.

Abstract: A method for verifying the integrity of a communication link is disclosed herein. In selected embodiments, such a method may include detecting, during normal operation of a communication link, a condition indicative of a high failure rate (HFR) on the communication link. The method may further include placing the communication link in an HFR state as a result of the condition. While in HFR state, the method may repeatedly transmit test I/Os over the communication link. The method may then automatically exit HFR state and resume normal operation on the communication link when one or more of the following has occurred: a selected number of test I/Os have been successfully transmitted over the communication link, and a number of test I/Os have been successfully transmitted over the communication link for a selected period of time. A corresponding system, apparatus, and computer program product are also disclosed and claimed herein.

Abstract: A method for replicating I/O performance in data replication environments, such as PPRC environments, is described. In selected embodiments, such a method includes monitoring I/O workload at a primary storage device over a period of time, such as a period of hours, days, or months. The method then generates learning data at the primary storage device describing the I/O workload over the selected time period. The learning data is replicated from the primary storage device to a secondary storage device. The method uses the learning data to optimize the secondary storage device to handle the I/O workload of the primary storage device. This will enable the secondary storage device to provide substantially the same I/O performance as the primary storage device in the event a failover occurs. A corresponding system and computer program product are also disclosed and claimed herein.

Abstract: A method for replicating I/O performance in data replication environments, such as PPRC environments, is described. In selected embodiments, such a method includes monitoring I/O workload at a primary storage device over a period of time, such as a period of hours, days, or months. The method then generates learning data at the primary storage device describing the I/O workload over the selected time period. The learning data is replicated from the primary storage device to a secondary storage device. The method uses the learning data to optimize the secondary storage device to handle the I/O workload of the primary storage device. This will enable the secondary storage device to provide substantially the same I/O performance as the primary storage device in the event a failover occurs.

Abstract: A method for providing rolling continuous data protection of source data is disclosed. In one embodiment, such a method includes enabling a user to select source data and establish a first interval when point-in-time copies of the source data are generated. The method further enables the user to specify a first number of point-in-time copies to retain at the first interval. The method further enables the user to specify a second number of point-in-time copies to retain at a second interval, wherein the second interval is a (n?2) multiple of the first interval. The method further enables the user to specify a third number of point-in-time copies to retain at a third interval, wherein the third interval is a (n?2) multiple of the second interval. A corresponding apparatus and computer program product are also disclosed.

Abstract: A method to maintain write operation atomicity where a write operation crosses a data storage medium track boundary. The method supplies a storage controller comprising a host adapter, a processor, and a NVS. The host adapter receives from a host computer a write request and data. The method determines if the write request will cross a data storage medium track boundary. If the write request will cross a data storage medium track boundary, the method indicates to the host adapter that the write request comprises a two-track transfer, and writes the data to the NVS as the data is received. If the host computer fails prior to providing all the data to the storage controller, the method discards the data written to the NVS to ensure write operation atomicity.

Abstract: Provided are a method, system, and article of manufacture for splitting writes between a storage controller and replication engine. A splitter executing in a storage controller manages access to primary volumes. An initialization command is received to communicate with a replication engine. A replication command is received for one primary volume and the primary volume is indicated as subject to replication. A write request is received to write data to a target primary volume of the primary volumes that is indicated as subject to the replication. The data in the write request is written to the target primary volume. The data in the write request is sent to the replication engine. The replication engine executes a copy services function associated with the target primary volume to write the data to a replication engine volume.

Abstract: Provided is a method for maintaining mirror and storage system copies of volumes at multiple remote sites. A first server maintains a mirror copy relationship between a first storage system at a first site and a second storage system at a second site. The first server performs a first point-in-time copy operation from the first storage system to a first storage system copy, wherein the data for the first storage system copy is consistent as of the determined point-in-time. The first server transmits a command to a second server to create a point-in-time copy of the second storage system. The second server processes mirror data transferred from the first server as part of the mirror copy relationship to determine when to create a second point-in-time copy. The second server performs the second point-in-time copy operation.

Abstract: Provided are a method, system, and article of manufacture for determining whether to use a repository to store data updated during a resynchronization. Writes to a primary storage are transferred to a secondary storage. A logical copy of the secondary storage as of a point-in-time is established. Writes to the secondary storage in the logical copy received from the primary storage during a logical copy duration after the point-in-time are stored in a repository that comprises less storage space than the secondary storage in the logical copy. The transferring of writes to the secondary storage is suspended. During the suspension writes to the primary storage are indicated in an out-of-synch data structure.

Abstract: Provided are a method, system, and article of manufacture for managing writes received to data units that are being transferred to a secondary storage as part of a mirror relationship. Synchronization information indicates data units to transfer from a primary storage to a secondary storage, wherein the synchronization information data is updated to indicate the transfer of one of the data units from the primary storage to the secondary storage. A storage controller receives a write request having an update to a target data unit comprising one of the data units indicated in the synchronization information that has not been transferred from the primary storage to the secondary storage. The write request is allowed to apply the update to the target data unit in response to transferring the data in the target data unit to a network adapter of the storage controller and before the data in the target data unit is transferred to the secondary storage.

Abstract: Provided are a system and article of manufacture for mirroring data. A mirror policy indicating volumes in a first storage system is processed to mirror to volumes in a second storage system and volumes in the second storage system to mirror to volumes in a third storage system. The third storage system is at a first geographical location remote with respect to a second geographical location including the first and second storage systems. A command is transmitted to cause the copying of updates to the volumes in the first storage system to corresponding volumes in the second storage system indicated in the mirror policy. Upon an occurrence of an event, the causing the suspension of the copying of updates to the volumes in the first storage system indicated in the mirroring policy to the volumes in the second storage system.

Abstract: Provided are a method, system, and article of manufacture for splitting writes between a storage controller and replication engine. A splitter executing in a storage controller manages access to primary volumes. An initialization command is received to communicate with a replication engine. A replication command is received for one primary volume and the primary volume is indicated as subject to replication. A write request is received to write data to a target primary volume of the primary volumes that is indicated as subject to the replication. The data in the write request is written to the target primary volume. The data in the write request is sent to the replication engine. The replication engine executes a copy services function associated with the target primary volume to write the data to a replication engine volume.

Abstract: Provided are a computer program product, system, and method for maintaining mirror and storage system copies of volumes at multiple remote sites. A first server maintains a mirror copy relationship in a computer readable storage medium between a first storage system at a first site and a second storage system at a second site to mirror data at the first storage system to the second storage system, wherein the first and second sites connect over a network. The first server performs a first point-in-time copy operation from the first storage system to a first storage system copy, wherein the data for the first storage system copy is consistent as of the determined point-in-time, wherein the point-in-time copy operation is completed upon creating a data structure indicating data for the first storage system copy as located at the first storage or the first storage system copy. The first server transmits a command to a second server to create a point-in-time copy of the second storage system.

Abstract: Provided are a method, system, and article of manufacture for splitting writes between a storage controller and replication engine. A splitter executing in a storage controller manages access to primary volumes. An initialization command is received to communicate with a replication engine. A replication command is received for one primary volume and the primary volume is indicated as subject to replication. A write request is received to write data to a target primary volume of the primary volumes that is indicated as subject to the replication. The data in the write request is written to the target primary volume. The data in the write request is sent to the replication engine. The replication engine executes a copy services function associated with the target primary volume to write the data to a replication engine volume.

Abstract: Provided is a system and article of manufacture for mirroring data. A mirror policy indicating volumes in a first storage system is processed to mirror to volumes in a second storage system and volumes in the second storage system to mirror to volumes in a third storage system. The third storage system is at a first geographical location remote with respect to a second geographical location including the first and second storage systems. A command is transmitted to cause the copying of updates to the volumes in the first storage system to corresponding volumes in the second storage system indicated in the mirror policy. Upon an occurrence of an event, the causing the suspension of the copying of updates to the volumes in the first storage system indicated in the mirroring policy to the volumes in the second storage system.

Abstract: Provided are a method, system, and article of manufacture for a replication engine communicating with a splitter to split writes between a storage controller and replication engine. Communication is initiated with the splitter implemented in a storage controller managing access to primary volumes. A command is sent to the splitter to copy writes to one primary volume to the replication engine. Write data is received from the splitter to one of the primary volumes following the splitter receiving the command to copy the writes to the replication engine. A determination is made of a copy services function to use for the received data. The determined copy services function is invoked to transfer the received data to a secondary storage volume.

Abstract: Techniques are provided for performing a copy operation. A fast reverse restore command indicating a new source and a new target is received, wherein the new source is an original target and the new target is an original source. A synchronous scan is performed on the new target. A new target structure associated with the new target is updated using a new source structure associated with the new source. Techniques are also provided for performing a copy operation in which a fast reverse restore command is received after an instant virtual copy has been performed from a new target to a new source and wherein the fast reverse restore command is performed before a background copy has been performed by the instant virtual copy.

Abstract: A method for synchronizing data storage systems is provided. The method comprises designating a relationship between a first data storage system and a second data storage system, such that data stored in the first data storage system is copied to the second data storage system, in response to determining that the data stored in the first data storage system has been modified; receiving a first request to modify data stored in a first data block of a first storage volume in the first data storage system, wherein the data block is modified according to the first request; determining that the first data block has not been successfully synchronized when the modified data stored in the first data block is not copied to the second data storage system; and executing a process to retry synchronization of the first data block until synchronization of the first data block is successful, without suspending the relationship while the process is executed.

Abstract: A method, system, and computer program product to preserve data integrity in a mirror and copy environment is disclosed herein. In one embodiment, a method may include receiving a write command and data from a host device. The method may further include writing the data to a primary storage device and attaching a primary sequence number associated with the primary storage device to the write command, thereby providing a numbered write command with a command sequence number. The numbered write command may then be transmitted to a secondary storage device. The method may further include comparing the command sequence number to a secondary sequence number associated with the secondary storage device. If the command sequence number matches the secondary sequence number, then the command may be executed. Otherwise, it may be ignored.