Abstract:
A target data storage system comprises a peer-to-peer communication link interface for linking the target to a source data storage system, and data storage for storing point in time copy data received from the source via the peer-to-peer communication link interface. Information is established at the target relating logical identification of the point in time copy data to point in time copy data stored at the target and to point in time copy data stored at the source, such that the information references the data storage system having requested point in time copy data. A controller of the target accesses requested point in time copy data at the target if the table indicates that the requested point in time copy data is available at the target; else obtains the requested point in time copy data from the source via the peer-to-peer communication link interface.
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:
Tracks of data or other data units are copied from a primary storage system to a secondary storage system. For multiple-track or multiple-data unit transfers, a group of tracks or data units which are sequentially related are transferred. A respective task is defined at the primary storage system for monitoring a progress of the transfer of each of the respective data units in a group. A state is maintained for monitoring a progress of the transfer of the group responsive to the progress of each of the tasks. A normal state is selected when there are no failed tasks. A recovery state is selected when there is a failure, and the status of the remaining tasks is being ascertained. A retry state is selected following the recovery state to retry the failed tasks. A failed state indicates an unrecoverable failure.
Abstract:
Disclosed is a technique for assigning priorities. A request to manipulate data is received. A type of the request is determined. A priority is assigned to the request based on the type of the request.
Abstract:
A method of recovery from a data storage system failure in a data storage system having a host computer writing data to a first storage unit with a first storage controller synchronously mirroring the data to a second storage unit, and with a second storage controller asynchronously mirroring the data to a third storage unit. The method begins with the detection of a failure associated with the first storage unit. Upon detection of the error or failure associated with the first storage unit, the synchronous data mirroring relationship between the first storage unit and the second storage unit is terminated and the host is directed to write data updates directly to the second storage unit. Upon correction of the failure associated with the first storage unit, the asynchronous mirroring of data updates from the second storage unit to the third storage unit is suspended and synchronous mirroring of the data updates in a reverse direction, from the second storage unit to the first storage unit, is commenced. When a full duplex state is reached between the first storage unit and the second storage unit, the synchronous PPRC relationship with the first storage volume mirroring data to the second storage volume may be reestablished and host I/O writes to the first storage unit may be resumed.
Abstract:
A data storage system which copies data from source data storage volumes to target data storage volumes restricts a write operation to at least one source data storage volume (FREEZE), to prevent the updating of a source while the data of a consistency group of interdependent data is being copied. Program logic selects a source data storage volume to which the restriction applies as a verification volume; and the program logic responds to a verification request to first employ the verification volume to verify that the restriction remains in place with respect to the verification volume, and to allow a reset of the restriction (THAW).
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:
An apparatus, system, and method are disclosed for replicating point-in-time copies of local data to a remote site. The present invention mirrors point-in-time copy directives on the local data store to initiate a point-in-time copy operation on the remote copy of the local data, thereby efficiently providing remote access to a point-in-time copy of a dataset. Data integrity is ensured by committing local and remote point-in-time copy operations subsequent to successful initiation of both local and remote point-in-time copy operations. The present invention also, in one embodiment, rolls back a point-in-time copy operation in response to a failure to replicate the copy operation.
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 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.