US 11,531,474 B1Granted

Storage system and data replication method in storage system

AssigneeHitachi, Ltd.

InventorsTakaki Matsushita, Yusuke Yamaga

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Abstract

In a storage system, processing related to data replication includes associating first control information with a logical volume and a snapshot and second control information with data on a pool volume. Data of the logical volume and the snapshot is managed by associating the first control information with the second control information. A time series of the logical volume and one or more snapshots is managed using generation information associated with the first control information, for each piece of data on the pool volume. Generation information indicating a generation in which the data is created is managed in association with the second control information. Invalidation of the first and second control information asynchronously with a processing of data related to the logical volume and the snapshot is executed. Whether the invalidation is possible is determined by referring to the generation information associated with the first and second control information.

Claims7

Dependent claims

A storage system, comprising:

a controller configured to provide a logical volume to a host device;
and
a physical storage device configured to store data,
the storage system being capable of creating a snapshot which is a duplicate of the logical volume, wherein
the controller is configured to:
form a pool volume corresponding to the logical volume using the physical storage device;
store first control information associated with the logical volume and the snapshot and second control information associated with data on the pool volume;
manage data of the logical volume and the snapshot by associating the first control information with the second control information;
manage a time series of the logical volume and one or a plurality of snapshots using generation information associated with the first control information;
manage, for each piece of data on the pool volume, generation information indicating a generation in which the data is created in association with the second control information;
execute invalidation of the first control information and/or the second control information asynchronously with a processing of data related to the logical volume and/or the snapshot;
determine whether the invalidation is possible by referring to the generation information associated with the first control information and generation information associated with the second control information in the invalidation;
and
when a generation of the first control information to be invalidated is specified as a target generation, determine whether the invalidation is possible based on a reference state in a one-generation old generation in a direct system of the target generation and a reference state in a one-generation new generation in the direct system of the target generation.

11 more elements

A storage system, comprising:

a controller configured to provide a logical volume to a host device;
and
a physical storage device configured to store data,
the storage system being capable of creating a snapshot which is a duplicate of the logical volume, wherein
the controller is configured to:
form a pool volume corresponding to the logical volume using the physical storage device;
store first control information associated with the logical volume and the snapshot and second control information associated with data on the pool volume;
manage data of the logical volume and the snapshot by associating the first control information with the second control information;
manage a time series of the logical volume and one or a plurality of snapshots using generation information associated with the first control information;
manage, for each piece of data on the pool volume, generation information indicating a generation in which the data is created in association with the second control information;
execute invalidation of the first control information and/or the second control information asynchronously with a processing of data related to the logical volume and/or the snapshot;
determine whether the invalidation is possible by referring to the generation information associated with the first control information and generation information associated with the second control information in the invalidation;
when writing is performed in the logical volume, store data to be written in a new area of the pool volume, associate an address of a write destination in the logical volume with the data to be written and associate a generation of the logical volume with the second control information by switching a correspondence relationship between the first control information and the second control information;
set second control information whose correspondence relationship with the first control information is canceled by switching the correspondence relationship as a target of the invalidation;
and
determine that the invalidation is possible if a generation of the second control information to be invalidated matches a generation associated with the first control information of the logical volume by comparison.

13 more elements

A storage system, comprising:

a controller configured to provide a logical volume to a host device;
and
a physical storage device configured to store data,
the storage system being capable of creating a snapshot which is a duplicate of the logical volume, wherein
the controller is configured to:
form a pool volume corresponding to the logical volume using the physical storage device;
store first control information associated with the logical volume and the snapshot and second control information associated with data on the pool volume;
manage data of the logical volume and the snapshot by associating the first control information with the second control information;
manage a time series of the logical volume and one or a plurality of snapshots using generation information associated with the first control information;
manage, for each piece of data on the pool volume, generation information indicating a generation in which the data is created in association with the second control information;
execute invalidation of the first control information and/or the second control information asynchronously with a processing of data related to the logical volume and/or the snapshot;
determine whether the invalidation is possible by referring to the generation information associated with the first control information and generation information associated with the second control information in the invalidation
manage latest generation information;
when restoring the logical volume from the snapshot, duplicate first control information of a snapshot of a restore source, associate the first control information with the logical volume, and increment the latest generation information;
specify the generation information of the first control information associated with the logical volume before the restoration as an invalidation target generation of the invalidation;
and
when a generation associated with the second control information is newer than a one-generation old generation in a direct system of the target generation by comparison and is not referred to from a one-generation new generation in the direct system of the target generation, determine that the invalidation is possible for the second control information associated with the first control information of the target generation.

14 more elements

A storage system, comprising:

a controller configured to provide a logical volume to a host device;
and
a physical storage device configured to store data,
the storage system being capable of creating a snapshot which is a duplicate of the logical volume, wherein
the controller is configured to:
form a pool volume corresponding to the logical volume using the physical storage device;
store first control information associated with the logical volume and the snapshot and second control information associated with data on the pool volume;
manage data of the logical volume and the snapshot by associating the first control information with the second control information;
manage a time series of the logical volume and one or a plurality of snapshots using generation information associated with the first control information;
manage, for each piece of data on the pool volume, generation information indicating a generation in which the data is created in association with the second control information;
execute invalidation of the first control information and/or the second control information asynchronously with a processing of data related to the logical volume and/or the snapshot;
determine whether the invalidation is possible by referring to the generation information associated with the first control information and generation information associated with the second control information in the invalidation;
when the snapshot is deleted, specify the generation information associated with the first control information of a deleted snapshot as an invalidation target generation of the invalidation;
and
when a generation associated with the second control information is newer than a one-generation old generation in a direct system of the target generation by comparison and is not referred to from a one-generation new generation in the direct system of the target generation, determine that the invalidation is possible for the second control information associated with the first control information of the target generation.

12 more elements

Dependencies are inferred from the claim text.