Abstract: Provided are a computer program product, system, and method for performing a failover between a first storage system and a second storage system. Data is synchronized between the first storage system and the second storage system. A failover is performed from the first storage system to the second storage system in response to a failover event at the first storage system while synchronizing the data. A determination is made that a first storage unit of the first storage system is inoperable and that that a second storage unit of the first storage system is operable in response to the failover event. In response to determining that the second storage unit is operable, a resynchronization is initiated to copy updates to a second storage unit of the second storage system mirroring the second storage unit of the first storage system to the second storage unit of the first storage system.

Abstract: Provided are a computer program product, system, and method for performing a failover between a first storage system and a second storage system. Data is synchronized between the first storage system and the second storage system. A failover is performed from the first storage system to the second storage system in response to a failover event at the first storage system while synchronizing the data. A determination is made that a first storage unit of the first storage system is inoperable and that that a second storage unit of the first storage system is operable in response to the failover event. In response to determining that the second storage unit is operable, a resynchronization is initiated to copy updates to a second storage unit of the second storage system mirroring the second storage unit of the first storage system to the second storage unit of the first storage system.

Abstract: Provided are a computer program product, system, and method for performing a failover between a first storage system and a second storage system. Data is synchronized between the first storage system and the second storage system. A failover is performed from the first storage system to the second storage system in response to a failover event at the first storage system while synchronizing the data. A determination is made that a first storage unit of the first storage system is inoperable and that that a second storage unit of the first storage system is operable in response to the failover event. In response to determining that the second storage unit is operable, a resynchronization is initiated to copy updates to a second storage unit of the second storage system mirroring the second storage unit of the first storage system to the second storage unit of the first storage system.

Abstract: A computer implemented method includes the steps of establishing a plurality of storage control sessions, wherein each storage control session associates at least one primary storage controller and at least one secondary storage controller with a predetermined path through a data transport network that interconnects the primary and secondary storage controllers; identifying storage control sessions that have data available to be transferred from primary storage controllers to secondary storage controllers; accumulating available data for each session and determining transfer time through the network for each data element to estimate prospective bandwidth utilization; and determining, for a predetermined time interval, whether transferring the available data would fully occupy available bandwidth of the data transport network for the predetermined time interval.

Abstract: Provided are a computer program product, system, and method for performing a failover between a first storage system and a second storage system. Data is synchronized between the first storage system and the second storage system. A failover is performed from the first storage system to the second storage system in response to a failover event at the first storage system while synchronizing the data. A determination is made that a first storage unit of the first storage system is inoperable and that that a second storage unit of the first storage system is operable in response to the failover event. In response to determining that the second storage unit is operable, a resynchronization is initiated to copy updates to a second storage unit of the second storage system mirroring the second storage unit of the first storage system to the second storage unit of the first storage system.

Abstract: Providing a computer program product, system, and method for setting copy permissions for target data in a copy relationship. Source data is copied from a first storage to a first data copy in a second storage. A request is received to copy requested data from the first data copy to a second data copy. The second copy operation is performed to copy the requested first data copy form the second storage to a second data copy in response to determining that the requested first data copy is not in the state that does not permit the copying. The request is denied in response to determining that the requested first data copy is in the state that does not permit copying.

Abstract: Providing a computer program product, system, and method for setting copy permissions for target data in a copy relationship. Source data is copied from a first storage to a first data copy in a second storage. A request is received to copy requested data from the first data copy to a second data copy. The second copy operation is performed to copy the requested first data copy form the second storage to a second data copy in response to determining that the requested first data copy is not in the state that does not permit the copying. The request is denied in response to determining that the requested first data copy is in the state that does not permit copying.

Abstract: For dynamically adjusting write pacing, a calculation module calculates an interval as a maximum threshold for a primary volume divided by a first maximum pacing level for a first importance level. The calculation module further calculates a first pacing level as a number of record sets that have not been mirrored to a secondary volume divided by the interval. The first pacing level is set to the first maximum pacing level if the first pacing level is greater than the first maximum pacing level. The calculation module also selects a first pacing delay associated with the first pacing level from a delay table. A pacing module delays writes for a first channel command word writing to the primary volume by the first pacing delay.

Abstract: Providing a computer program product, system, and method for setting copy permissions for target data in a copy relationship. Source data is copied from a first storage to a first data copy in a second storage. A request is received to copy requested data from the first data copy to a second data copy. The second copy operation is performed to copy the requested first data copy form the second storage to a second data copy in response to determining that the requested first data copy is not in the state that does not permit the copying. The request is denied in response to determining that the requested first data copy is in the state that does not permit copying.

Abstract: A computer implemented method includes the steps of establishing a plurality of storage control sessions, wherein each storage control session associates at least one primary storage controller and at least one secondary storage controller with a predetermined path through a data transport network that interconnects the primary and secondary storage controllers; identifying storage control sessions that have data available to be transferred from primary storage controllers to secondary storage controllers; accumulating available data for each session and determining transfer time through the network for each data element to estimate prospective bandwidth utilization; and determining, for a predetermined time interval, whether transferring the available data would fully occupy available bandwidth of the data transport network for the predetermined time interval.

Abstract: Providing a computer program product, system, and method for setting copy permissions for target data in a copy relationship. Source data is copied from a first storage to a first data copy in a second storage. A request is received to copy requested data from the first data copy to a second data copy. The second copy operation is performed to copy the requested first data copy form the second storage to a second data copy in response to determining that the requested first data copy is not in the state that does not permit the copying. The request is denied in response to determining that the requested first data copy is in the state that does not permit copying.

Abstract: For dynamically adjusting write pacing, a calculation module calculates an interval as a maximum threshold for a primary volume divided by a first maximum pacing level for a first importance level. The calculation module further calculates a first pacing level as a number of record sets that have not been mirrored to a secondary volume divided by the interval. The first pacing level is set to the first maximum pacing level if the first pacing level is greater than the first maximum pacing level. The calculation module also selects a first pacing delay associated with the first pacing level from a delay table. A pacing module delays writes for a first channel command word writing to the primary volume by the first pacing delay.

Abstract: Providing a computer program product, system, and method for setting copy permissions for target data in a copy relationship. Source data is copied from a first storage to a first data copy in a second storage. A request is received to copy requested data from the first data copy to a second data copy. The second copy operation is performed to copy the requested first data copy form the second storage to a second data copy in response to determining that the requested first data copy is not in the state that does not permit the copying. The request is denied in response to determining that the requested first data copy is in the state that does not permit copying.

Abstract: A method, device, and computer program product for performing asynchronous remote copy verification is provided. An initial track-to-track comparison between a primary and a secondary volume pair is performed. A first predetermined time is waited for. Upon completion of the first predetermined time, a subsequent primary volume track-to-secondary volume track comparison is performed only on the noncompare tracks. A query is performed for determining whether all of the noncompare tracks have been resolved. If any of the noncompare tracks have not been resolved, a query is performed for determining if a predetermined number of iterations of the primary volume track-to-secondary volume track comparison have been performed, and an additional subsequent primary volume track-to-secondary volume track comparison is performed only on unresolved noncompare tracks.

Abstract: A method is disclosed to write data to an information storage and retrieval system comprising (n) volumes and a data cache, where that information storage and retrieval system is capable of communicating with one or more host computers. The method receives from a host computer an update for the (i)th volume, and determines the (i)th delay, where that (i)th delay is associated with the (i)th volume. The method then writes the update to said data cache interposing the (i)th delay without indicating to said host computer that the information storage and retrieval system is unavailable.

Abstract: An apparatus, system, and method are disclosed for regulating the number of write requests in a fixed-size cache that facilitates differentiated treatment of write requests based on an assigned pacing value. The apparatus includes an examination module to examine a pending write request issued by an application. A priority module determines a priority for the write request based on an operating system defined input/output priority value. An assessment module assesses a storage demand level for storing write requests in a fixed-size cache. An assignment module assigns a pacing value to the write request based on the priority and in response to the storage demand level. A permission module permits the application to issue a subsequent write request once the pacing value of the write request is satisfied. The pacing value is satisfied by waiting until the amount of time specified by the pacing value expires.