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 system and article of manufacture for copying storage. Copy operations are performed on source storage units to copy to target storage units, wherein the copy operations create a consistent copy of the source storage units in the target storage units. While performing a copy operation to copy from one source storage unit to one target storage unit, a write operation is restricted from being performed on the one source storage unit, until the copy operations have been performed on the source storage units.

Abstract: Provided are a method, system, and program for accessing a resource. Requests are generated to access a resource in a first access mode and a second access mode. The requests are processed to access the resource in the second mode before processing at least one request to access the resource in the first access mode. The processing of the requests to access the resource in the first access mode is delayed for a time period after processing all the requests to access the resource in the second access mode in order to wait to receive a subsequent request to access the resource in the second access mode.

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 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: 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 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 is a method for copying storage. Copy operations are performed on source storage units to copy to target storage units, wherein the copy operations create a consistent copy of the source storage units in the target storage units. While performing a copy operation to copy from one source storage unit to one target storage unit, a write operation is restricted from being performed on the one source storage unit, until the copy operations have been performed on the source storage units.

Abstract: Provided is a method 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: 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: Techniques are provided for performing a copy operation. An instant virtual copy operation is issued from a first portion of data to a primary mirroring portion of data, wherein the primary mirroring portion of data corresponds to a secondary mirroring portion of data, and wherein the primary mirroring portion of data and the secondary mirroring portion of data are in a mirroring relationship. The mirroring relationship is transitioned to a duplex pending state in response to determining that the mirroring relationship is in a full duplex state. When the mirroring relationship is in a duplex pending state, each block of data involved in the instant virtual copy operation is transferred from the primary mirroring portion of data to the secondary mirroring portion of data.

Abstract: Provided are a method, system, and article of manufacture, wherein synchronous replication of data is initiated from a first site to a second site. At least one part of the data is sent asynchronously from the second site to a third site, wherein the asynchronously sent at least one part of the data is stored at the second site while the at least one part of data is in flight from the second site to the third site. The at least one part of the data stored at the second site is deleted, in response to the at least one part of the data being securely stored at the third site.

Abstract: Provided are a method, system, and program for managing resources in which a local processor sends remote operation requests to be executed by a remote processor having multiple resources. In the illustrated embodiment, the local processor and the remote processor each have a resource manager, each of which maintains a control set for each resource of the remote processor. Each control set of the remote processor resource manager includes a queue for queuing remote operation requests awaiting execution in connection with the resource associated with the control set. Each control set of the local processor resource manager includes a credit counter which keeps track of permissible outstanding remote operation requests. Each local processor control set credit counter is decremented for each remote operation request for the associated resource sent to the remote processor and is incremented for each acknowledgment received from the remote processor.

Abstract: An apparatus, system, and method are disclosed for activating a synchronous mirror as a primary storage volume. The apparatus system and method include directing a third storage volume to store updates sent to the third storage volume from a second storage volume onto a first storage volume in response to the first storage volume becoming operational after a failure, terminating sending updates from the second storage volume to the third storage volume in response to the first storage volume becoming substantially consistent with the third storage volume, and synchronously storing updates received by the second storage volume on the first storage volume and asynchronously storing updates received by the first storage volume on the third storage volume in response to terminating sending updates from the second storage volume to the third storage volume after the first and third storage volumes are substantially consistent.

Abstract: Provided are a method, system, and article of manufacture for copying storage. Data sent from a first storage unit is synchronously copied at a second storage unit. The copied data is sent asynchronously from the second storage unit to a third storage unit.

Abstract: An apparatus, system and method for synchronizing an asynchronous mirror volume using a synchronous mirror volume by tracking change information when data is written to a primary volume and not yet written to an asynchronous mirror, and storing the change information on both the primary storage system and the synchronous mirror system. In the event the primary storage system becomes unavailable, the asynchronous mirror is synchronized by copying data identified by the change information stored in the synchronous mirror system and using the synchronous mirror as the copy data source.

Abstract: Provided are a method, system, and program for forming a consistency group of data. A command is received to form a consistency group with respect to data received at a first storage site that is mirrored to a second storage site. A first data structure is provided indicating updates to the first storage site not included in the consistency group that are received after the command and a second data structure is provided indicating updates to the first storage site in the consistency group to be formed. A command is transmitted to cause data copied to the second storage site that is part of the consistency group to be copied to a third storage site. Indication is received when the data in the second storage site that is part of the consistency group is copied to the third storage site.

Abstract: Provided are a method, system, and article of manufacture for copying data. A request is received at a first storage control unit having a first set of volumes, wherein the first storage unit is coupled via a link to a second storage control unit having a second set of volumes that are peer-to-peer copies of the first set of volumes, and wherein the request is for generating a copy of the first and second set of volumes in a third set of volumes in the second storage control unit. A command is transmitted via the link, from the first storage control unit to the second storage control unit, wherein the transmitted command is capable of causing the second storage control unit to generate the copy of the first and second set of volumes in the third set of volumes in the second storage control unit.

Abstract: Provided are a method, system, and program for forming a consistency group of data. Information is provided on a consistency group relationship indicating a plurality of slave controllers and, for each indicated slave controller, a slave storage unit managed by the slave controller. A command is transmitted to each slave controller in the consistency group relationship to cause each slave controller to transmit data in the slave storage unit to a remote storage in a manner that forms the consistency group. A determination is made as to whether all the slave controllers successfully transmitted the data in the slave storage units that is part of the consistency group to the remote storage.

Abstract: Provided are a method, system, and article of manufacture for copying storage. Copy operations are performed on source storage units to copy to target storage units, wherein the copy operations create a consistent copy of the source storage units in the target storage units. While performing a copy operation to copy from one source storage unit to one target storage unit, a write operation is restricted from being performed on the one source storage unit, until the copy operations have been performed on the source storage units.