International Business Machines Corporation

Christopher B Beeken

John Paul Agombar

Carlos Francisco Fuente

William James Scales

David John Carr

John P Wilkinson

Simon Walsh

Stephanie Machleidt

Joanna Katharine Brown

Denis A Frank

Robert Bruce Nicholson

Point-in-time backup copies of a production volume that include volume maps between adjacent source and target volumes can be created in a cascade of data volumes. An empty volume map having the backup copy as the target can be created. The empty volume map can include a first bitmap used to indicate that data is stored in the source or the target, a second bitmap for use in managing and optimizing background copying, and an index for tracking a status of background copying. The volume map can be populated so that the first bitmap indicates data is stored in the source, and the index set to a start value. Production volume data regions can be sequentially background copied to the backup copy, while tracking using the index. Upon backup copy completion, the values of the volume map having the backup copy as the target can be stored.

Managing backup copies in cascaded data volumes

Point-in-time backup copies of a production volume that include volume maps between adjacent source and target volumes can be created in a cascade of data volumes. An empty volume map having the backup copy as the target can be created. The empty volume map can include a first bitmap used to indicate that data is stored in the source or the target, a second bitmap for use in managing and optimizing background copying, and an index for tracking a status of background copying. The volume map can be populated so that they first bitmap indicates data is stored in the source, and the index set to a start value. Production volume data regions can be sequentially background copied to the backup copy, while tracking using the index. Upon backup copy completion, the values of the volume map having the backup copy as the target can be stored.

In one aspect of the present description, handling multiple backup processes comprises detecting that a defined storage volume is present in a first cascade of storage volumes; detecting that the defined storage volume is present in a second cascade of storage volumes; receiving a data write for a last storage volume in the first cascade of storage volumes; and performing a cleaning data write on the defined storage volume in the second cascade of storage volumes, wherein the cleaning data write corresponds to the received data write. Other aspects may be utilized, depending upon the particular application.

Restore in cascaded copy environment

A system and computer program product of handling multiple backup processes have been provided. The system comprises receiving one or more instructions initiating a plurality of backup processes from a single source storage volume to a plurality of target storage volumes, adding each target storage volume to a cascade of target storage volumes from the source storage volume, the target storage volumes added to the cascade in an order inversely proportional to the copy rate of the respective backup process such that a first target storage volume added to the cascade of target storage volumes has a slowest copy rate, a next added target storage volume to the cascade of target storage volumes has a faster copy rate than an immediately prior added target storage volume, and a most recent target storage volume added to the cascade of target storage volumes has a fastest copy rate.

Cascade ordering

A method comprises creating a cascade of target storage volumes from a plurality of target storage volumes by inserting each most recent target storage volumes between a last added target storage volume and a source storage volume, the most recent target storage volumes each having a copy rate faster than the last added target storage volume, such that each added target storage volume has a faster copy rate than an immediately prior added target storage volume, and a most recent target storage volume added to the cascade of target storage volumes has a fastest copy rate; and receiving one or more instructions initiating a plurality of backup processes from the source storage volume to a plurality of target storage volumes.

A method of handling multiple served backup processes comprising creating a cascade of target storage volumes from a plurality of target storage volumes by inserting each most recent target storage volumes between a last added target storage volume and a source storage volume, the most recent target storage volumes each having a copy rate faster than the last added target storage volume, such that each added target storage volume has a faster copy rate than an immediately prior added target storage volume, and a most recent target storage volume added to the cascade of target storage volumes has a fastest copy rate; and receiving one or more instructions initiating a plurality of served backup processes from the source storage volume to a plurality of target storage volumes.

A system, process, and product for source cleaning cascaded volumes include the ability to store a number of cascaded backup volumes and prepare received writes for storage. The system, process, and product also include the ability to examine a metadata set associated with a volume region for a write to determine whether another volume depends on the region and write the new data to the region if another volume is not dependent. The system, process, and product further include the ability to determine whether a write is for a volume region that is a canonical source and, if so, decrement a reference count in a metadata set associated with the region and establish the volume of the region as a canonical source for a metadata set associated with a new metadata set location identifier.

Source cleaning cascaded volumes using reference counts

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.

Source cleaning cascaded volumes using write and background copy indicators

A method comprises receiving one or more instructions initiating a plurality of backup processes from a single source storage volume to a plurality of target storage volumes, adding each target storage volume to a cascade of target storage volumes from the source storage volume, the target storage volumes added to the cascade in an order inversely proportional to the copy rate of the respective backup process, and starting each backup process in turn, the backup processes started in an order from the most recent target storage volume added to cascade to the first target storage volume added to cascade.

For handling multiple backup processes, computer-readable program code is described for receiving one or more instructions initiating a plurality of backup processes from a single source storage volume to a plurality of target storage volumes, adding each target storage volume to a cascade of target storage volumes from the source storage volume, the target storage volumes added to the cascade in an order inversely proportional to the copy rate of the respective backup process, and starting each backup process in turn, the backup processes started in an order from the most recent target storage volume added to cascade to the first target storage volume added to cascade.

Provided are a method, system, and a computer program product handling a backup process. An instruction initiates a new backup from a source volume to a target volume using one of a plurality of backup processes. A cascade includes a cascade source volume and at least one cascade target volume, and a write to a storage location in one of the cascade volumes causes a copying of the storage location to be written in the cascade source volume to each of the cascade target volumes in the cascade according to a cascade order in which the at least one cascade target volume and the cascade source volume are linked in the cascade. The cascade is modified to include the target volume of the new backup in response to determining that there is an existing cascade, else a new cascade using the backup process of the new backup is created.

Multiple cascaded backup process

Provided are a method, system, and a computer program product handling a backup process. An instruction is received initiating a new backup from a source volume to a target volume using one of a plurality of backup processes. A determination is made as to whether there is a cascade of volumes using the backup process including the source volume of the new backup. The cascade includes a cascade source volume and at least one cascade target volume, and a write to a storage location in one of the cascade volumes causes a copying of the storage location to be written in the cascade source volume to each of the cascade target volumes in the cascade according to a cascade order in which the at least one cascade target volume and the cascade source volume are linked in the cascade. The cascade, using the backup process of the new backup already including the source volume of the new backup, is modified to include the target volume of the new backup in response to determining that there is the existing cascade. A new cascade using the backup process of the new backup including the source volume and the target volume of the new backup is created in response to determining that there is not the existing cascade.

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Winchester, United Kingdom

Christopher B Beeken