Abstract: A method and system for storage copy with chain cloning are provided, including providing a volume with one or more snapshots in the form of a dependency chain, where the volume and one or more snapshots are volume nodes in the dependency chain and providing associated metadata required to maintain the one or more snapshots; cloning the dependency chain to create at least one a sparse copy chain including sparse copies of the volume and the one or more snapshots resulting in sparse volume nodes, resulting in a lattice structure of the dependency chain of volume nodes and one or more sparse copy chains of cloned volume nodes.

Abstract: A system, method, and computer program product for managing storage volumes in a point-in-time copy cascade. A processor swaps a host portion of a source volume with a host portion of a snapshot point-in-time copy volume. Responsive to an I/O request to overwrite a first data value in a grain of the source volume with a second data value, a processor writes the second data value in a corresponding grain of the snapshot point-in-time copy volume. Responsive to a corresponding grain of a clone point-in-time copy volume not comprising the first data value, a processor copies the first data value to the corresponding grain of the clone point-in-time copy volume.

Abstract: A system, method, and computer program product for managing storage volumes. A processor creates a first point-in-time copy cascade, where the first point-in-time copy cascade comprises a source volume, a first snapshot point-in-time copy volume, and a second snapshot point-in-time copy volume; the first volume is a snapshot copy of the source volume and the second volume is a snapshot copy of the first volume; and the source volume, the first volume, and the second volume include a host portion. A processor creates a third snapshot point-in-time copy volume from the first volume. A processor maps the third volume to create a second cascade, wherein the second cascade comprises the source volume, the first volume, and the third volume but not the second volume. A processor directs an I/O operation for the first copy volume to the third volume.

Abstract: Managing storage volumes in a point-in-time copy cascade. The cascade includes a first source volume, a first target volume and a second target volume. The method detects a corruption of the first source volume and, if a first restoration of the first source volume from the first target volume is in progress, creates a third target volume from the second target volume and directs I/O operations for the first source volume to the third target volume. The first restoration is stopped. The first source volume is restored from the third target volume, and the third target volume is deleted.

Abstract: Managing storage volumes in a point-in-time copy cascade. The cascade includes a first source volume, a first clone point-in-time target volume, and a second point-in-time target volume that is a point-in-time copy of the first point-in-time target volume. Grain background copies from the first source volume to the first clone point-in-time target volume are tracked, and, if the first clone point-in-time target volume is corrupted, a third point-in-time target volume is created from the second point-in-time target volume. I/O for the first clone point-in-time target volume is directed to the third point-in-time target volume. The first clone point-in-time target volume is cleaned to the second point-in-time target volume. The first clone point-in-time target volume is restarted from the third point-in-time target volume and each grain of the first clone point-in-time target volume that has not been background copied is copied from the cascade to the first clone point-in-time target volume.

Abstract: Managing storage volumes in a point-in-time copy cascade. The cascade includes a first source volume, a first point-in-time target volume, and a second point-in-time target volume. The second point-in-time target volume is a point-in-time copy of the first point-in-time target volume. Upon detecting a corruption of the first point-in-time target volume the method creates a third point-in-time target volume from the second point-in-time target volume and directs I/O operations for the first point-in-time target volume to the third point-in-time target volume. The first point-in-time target volume is restored to the second point-in-time target volume and, when the restoration is complete, deletes the first point-in-time target volume.

Abstract: A system is provided for transforming an in-use RAID array from a first array configuration having a first parameter to a second array configuration having a second parameter while preserving a logical data structure of the RAID array. The system includes an extent reservation component, and a data migration component for reading unmigrated data from an area of an array arranged according to the first array configuration and writing the data to an area of the array arranged according to the second array configuration using reserved extents to store migrated data. The system also includes a first I/O component for performing I/O according to the first array configuration on unmigrated data prior to its reading by the data migration component, and a second I/O component for performing I/O according to the second array configuration on the migrated data after writing the migrated data.

Abstract: Disclosed is a system for replicating data. The system may comprise a plurality of nodes preferably organized 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 authorizes 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 system is provided for transforming an in-use RAID array from a first array configuration having a first parameter to a second array configuration having a second parameter while preserving a logical data structure of the RAID array. The system includes an extent reservation component, and a data migration component for reading unmigrated data from an area of an array arranged according to the first array configuration and writing the data to an area of the array arranged according to the second array configuration using reserved extents to store migrated data. The system also includes a first I/O component for performing I/O according to the first array configuration on unmigrated data prior to its reading by the data migration component, and a second I/O component for performing I/O according to the second array configuration on the migrated data after writing the migrated data.

Abstract: A system is provided for transforming an in-use RAID array from a first array configuration having a first parameter to a second array configuration having a second parameter while preserving a logical data structure of the RAID array. The system includes an extent reservation component, and a data migration component for reading unmigrated data from an area of an array arranged according to the first array configuration and writing the data to an area of the array arranged according to the second array configuration using reserved extents to store migrated data. The system also includes a first I/O component for performing I/O according to the first array configuration on unmigrated data prior to its reading by the data migration component, and a second I/O component for performing I/O according to the second array configuration on the migrated data after writing the migrated data.

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 mechanism is provided for controlling a solid state disk. A failure detector detects a failure in the solid state disk. Responsive to failure detector detecting a failure, a status degrader sets a degraded status indicator for the solid state disk. Responsive to the degraded status indicator, a degraded status controller maintains the solid state disk in operation in a degraded operation mode.

Abstract: A mechanism is provided for controlling a solid state disk. A failure detector detects a failure in the solid state disk. Responsive to failure detector detecting a failure, a status degrader sets a degraded status indicator for the solid state disk. Responsive to the degraded status indicator, a degraded status controller maintains the solid state disk in operation in a degraded operation mode.

Abstract: Transforming an in-use RAID array from a first array configuration having a first parameter to a second array configuration having a second parameter while preserving the logical data structure. An extent reservation component and data migration component are provided for reading unmigrated data from an area of an array arranged according to the first array configuration and writing the data to an area of the array arranged according to the second array configuration using reserved extents to store first migrated data and using further extents to store second migrated data. A first I/O component for performing I/O according to the first array configuration on unmigrated data prior to its reading by the data migration component is provided along with a second I/O component for performing I/O according to the second array configuration on the first migrated data and the second migrated data after its writing by the data migration component.

Abstract: Mechanisms for ensuring data consistency in a data store are provided. The mechanisms access a parity scrub factor f and perform a check on a data group of the data store. The check on the data group includes performing a parity check on a portion of the data group, the portion being equal to 1/f of the data group, and performing a data verify on the remainder of the data group. The performing of the check is repeated for the entire data store. An offset factor is used to select the portion of the data group for the parity check. In this case, the offset factor may be incremented when the performance of the check on the data group of the data store has been repeated for the entire data store.

Abstract: A mechanism is provided for controlling a solid state disk. A failure detector detects a failure in the solid state disk. Responsive to failure detector detecting a failure, a status degrader sets a degraded status indicator for the solid state disk. Responsive to the degraded status indicator, a degraded status controller maintains the solid state disk in operation in a degraded operation mode.

Abstract: Mechanisms for ensuring data consistency in a data store are provided. The mechanisms access a parity scrub factor f and perform a check on a data group of the data store. The check on the data group includes performing a parity check on a portion of the data group, the portion being equal to 1/f of the data group, and performing a data verify on the remainder of the data group. The performing of the check is repeated for the entire data store. An offset factor is used to select the portion of the data group for the parity check. In this case, the offset factor may be incremented when the performance of the check on the data group of the data store has been repeated for the entire data store.