Abstract: Various systems, processes, and products may be used to source clean cascaded volumes. In particular implementations, a system, process, and product for source cleaning cascaded volumes may include the ability to store a primary volume and a plurality of cascaded backup volumes. The system, process, and product may also include the ability to determine whether a write to one of the backup volumes is due to a background copy being made of another volume in the cascade and adjust a background copy indicator in a volume map for the backup volume if the write is due to a background copy and to determine whether a write to one of the backup volumes is due to a write to another volume in the cascade and adjust a write copy indicator in a volume map for the backup volume if the write is due to a write to another cascaded volume.

Abstract: Various systems, processes, and products may be used to source clean cascaded volumes. In particular implementations, a system, process, and product for source cleaning cascaded volumes may include the ability to store a primary volume and a plurality of cascaded backup volumes. The system, process, and product may also include the ability to determine whether a write to one of the backup volumes is due to a background copy being made of another volume in the cascade and adjust a background copy indicator in a volume map for the backup volume if the write is due to a background copy and to determine whether a write to one of the backup volumes is due to a write to another volume in the cascade and adjust a write copy indicator in a volume map for the backup volume if the write is due to a write to another cascaded volume.

Abstract: Disclosed is a system for replicating data. The system may comprise a plurality of nodes preferably organised in groups with one of the nodes acting as a coordinator node. The nodes are configured to receive write requests from an external server and to apply these write requests to a data storage source of the data storage system. The write requests typically belong to a batch of independent write actions identified by a batch sequence number. Each node stores the write request in non-volatile memory with the coordinator node monitoring which batches are secured in their entirety in non-volatile memory. The coordinator node authorises all other nodes to sequentially replicate the write requests in their non-volatile memory to the data storage source for all writes up to the highest batch sequence number for which all writes have been secured in non-volatile memory.

Abstract: A method for optimizing cleaning of maps in storage cascades includes determining whether a target disk of a map contains data unavailable to a downstream disk from an upstream disk in a cascade and detect whether the downstream disk has a copy of the data. Additionally, the method includes copying the data from the target disk to the downstream disk, if the target disk of the map contains data unavailable to the downstream disk from the upstream disk and the downstream disk does not have the copy of the data. Furthermore, the method includes copying the data from the target disk to the downstream disk, if the target disk of the map does not contain data unavailable to the downstream disk from the upstream disk or the downstream disk does have the copy of the data. Moreover, the method includes removing the map from the cascade.

Abstract: A method for optimizing cleaning of maps in storage cascades includes determining whether a target disk of a map contains data unavailable to a downstream disk from an upstream disk in a cascade and detect whether the downstream disk has a copy of the data. Additionally, the method includes copying the data from the target disk to the downstream disk, if the target disk of the map contains data unavailable to the downstream disk from the upstream disk and the downstream disk does not have the copy of the data. Furthermore, the method includes copying the data from the target disk to the downstream disk, if the target disk of the map does not contain data unavailable to the downstream disk from the upstream disk or the downstream disk does have the copy of the data. Moreover, the method includes removing the map from the cascade.

Abstract: A technique for handling a FlashCopy® process includes receiving a FlashCopy® instruction for a source disk, performing a FlashCopy® point in time copy of the source disk on to a target disk, creating a map specifying the FlashCopy® point in time copy from the source disk to the target disk, creating a primary fdisk for the source disk, if one does not already exist, and creating a primary fdisk for the target disk, if one does not already exist, or, if one does already exist, converting the existing primary fdisk for the target disk into a secondary fdisk, and creating a new primary fdisk for the target disk.

Abstract: A method for optimizing cleaning of maps in FlashCopy cascades includes determining whether a target disk of a map contains data unavailable to a downstream disk from an upstream disk in a FlashCopy cascade and detect whether the downstream disk has a copy of the data. Additionally, the method includes copying the data from the target disk to the downstream disk, if the target disk of the map contains data unavailable to the downstream disk from the upstream disk and the downstream disk does not have the copy of the data. Furthermore, the method includes copying the data from the target disk to the downstream disk, if the target disk of the map does not contain data unavailable to the downstream disk from the upstream disk or the downstream disk does have the copy of the data. Moreover, the method includes removing the map from the FlashCopy cascade.

Abstract: A technique for handling a FlashCopy® process includes receiving a FlashCopy® instruction for a source disk, performing a FlashCopy® point in time copy of the source disk on to a target disk, creating a map specifying the FlashCopy® point in time copy from the source disk to the target disk, creating a primary fdisk for the source disk, if one does not already exist, and creating a primary fdisk for the target disk, if one does not already exist, or, if one does already exist, converting the existing primary fdisk for the target disk into a secondary fdisk, and creating a new primary fdisk for the target disk.

Abstract: A storage control apparatus in cooperation with a plurality of controlled storage apparatus arranged in a cascade of point-in-time copy relationship. The apparatus includes: a rate control component operable to set a desired rate for cleaning a first target one of the plurality of controlled storage apparatus; a comparator component in communication with the rate control component to identify discrepant bits associated with first and second targets; and a copy initiator, responsive to the comparator component to initiate a copy operation responsive to the identified discrepant bits.

Abstract: A mechanism is provided in a computing system for controlling virtualized storage operable to communicate with a host and with mapped and unmapped storage resource pools. A selection component selects a target for a destructive data storage operation from the mapped storage resource pool. Responsive to the selection of the target, a virtual targeting component creates a virtual target from the unmapped storage resource pool to represent the target. Responsive to the selection of the target, a storage move component moves the target to a protected storage resource pool. Responsive to the creation of the virtual target from the unmapped storage resource pool, storage move component, moves the virtual target to the used storage resource pool. The computing system then performs the destructive data storage operation on the virtual target.

Abstract: A method and system are provided for storage checkpointing in a mirrored virtual machine system. The method includes a storage controller receiving a modifying operation to storage from a virtual machine and carrying out the modifying operation in a non-destructive manner by saving the modifying operation data to a checkpointing region of storage and preserving the stored previous data state. The method also includes receiving a checkpoint notification and committing modifying operation data from the checkpointing region and releasing the stored previous data state. If a failover notification is received, the storage controller rolls back the physical storage to match a checkpoint state.

Abstract: Systems and methods to forward data frames are described. A particular method may include associating a fiber channel forwarder with a bridge element. The fiber channel forwarder may be one of a plurality of fiber channel forwarders coupled to the bridge element. A data frame received at the bridge element may be forwarded to the fiber channel forwarder.

Abstract: Various systems, processes, and products may be used to source clean cascaded volumes. In particular implementations, a system, process, and product for source cleaning cascaded volumes may include the ability to store a primary volume and a plurality of cascaded backup volumes. The system, process, and product may also include the ability to determine whether a write to one of the backup volumes is due to a background copy being made of another volume in the cascade and adjust a background copy indicator in a volume map for the backup volume if the write is due to a background copy and to determine whether a write to one of the backup volumes is due to a write to another volume in the cascade and adjust a write copy indicator in a volume map for the backup volume if the write is due to a write to another cascaded volume.

Abstract: Various systems, processes, and products may be used to source clean cascaded volumes. In particular implementations, a system, process, and product for source cleaning cascaded volumes may include the ability to store a primary volume and a plurality of cascaded backup volumes. The system, process, and product may also include the ability to determine whether a write to one of the backup volumes is due to a background copy being made of another volume in the cascade and adjust a background copy indicator in a volume map for the backup volume if the write is due to a background copy and to determine whether a write to one of the backup volumes is due to a write to another volume in the cascade and adjust a write copy indicator in a volume map for the backup volume if the write is due to a write to another cascaded volume.

Abstract: A method and system are provided for storage checkpointing in a mirrored virtual machine system. The method includes a storage controller receiving a modifying operation to storage from a virtual machine and carrying out the modifying operation in a non-destructive manner by saving the modifying operation data to a checkpointing region of storage and preserving the stored previous data state. The method also includes receiving a checkpoint notification and committing modifying operation data from the checkpointing region and releasing the stored previous data state. If a failover notification is received, the storage controller rolls back the physical storage to match a checkpoint state.

Abstract: Systems and methods to forward data frames are described. A particular method may include evaluating header data of a data frame at a bridge element, where the header data includes address data that corresponds to a Fiber Channel Forwarder in communication with the bridge element. Based upon the evaluation, the header data of the data frame may be modified at the bridge element in such a manner that the data frame is not routed through the Fiber Channel Forwarder.

Abstract: A backup control apparatus for periodic data backup, in a virtualized storage system having a point-in-time copy function operable to copy first data into a cascade, comprises a storage targeting component for selecting a target virtual disk for one of a full copy or an incremental copy of the first data; a periodic backup component for triggering a periodic point-in-time copy of the first data to a virtual disk in the cascade; a testing component for testing a status of the full copy, the incremental copy and the periodic point-in-time copy; and a cascade splitting component responsive to the status for splitting the cascade to remove a dependency relationship of at least one of the full copy, the incremental copy and the periodic point-in-time copy on the first data.

Abstract: A targeting storage component selects a target virtual disk for one of a full copy or an incremental copy of first data. A periodic backup component triggers a periodic point-in-time copy of the first data to a virtual disk in the cascade. A testing component tests a status of the full copy, the incremental copy and the periodic point-in-time copy. Responsive to the status, a cascade splitting component splits the cascade to remove a dependency relationship of at least one of the fully copy, the incremental copy and the periodic point-in-time copy on the first data.

Abstract: Methods and apparatus are provided for copying data from a primary storage facility to a secondary storage facility which reduce the workload on the storage controller in the primary facility and minimize bandwidth usage. The primary storage facility includes a primary data replication appliance which transfers data to a secondary replication appliance. Updated data from a host is both stored through a storage controller in the primary facility and also received by the primary replication appliance. Logic in the primary replication appliance determines whether the immediately previous version of the data is in a buffer from a previous storage operation. If so, the current (updated) version of the data is compared with the previous version and the difference, such as calculated through a bit-wise exclusive-OR operation, is transferred to the secondary replication appliance.

Abstract: An apparatus, method and computer program operable in a network controls consistency guarantees of a plurality of data copies in a storage apparatus, and includes: a lease control component for extending a lease to the storage apparatus; and a consistency freeze/thaw component responsive to a failure indication for initiating a consistency freeze action at the storage apparatus prior to expiration of the current group lease period. It may further include a timer component for waiting the apparatus for a predetermined period after the consistency freeze action, where the consistency freeze/thaw component is operable to initiate a thaw action at the storage apparatus.