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US 7,454,582 B2Granted
Initial copy system
AssigneeHitachi, Ltd.
InventorsYasuo Watanabe, Takashige Iwamura, Shunji Kawamura
Life of this patent
Estimating the term…
Abstract
A storage apparatus installed in a first site generates a snapshot of a copy source logical device in an intermediate logical device. Next, an external storage apparatus including a logical device corresponding to the intermediate logical device is disconnected from the first site and connected to the second site. A storage apparatus in the second site is made to recognize the logical device in the external storage device as a logical device of a remote copy target. Next, the storage apparatus instructs the second site about writing in the copy target logical device through a global network on the basis of the difference data managed with the bit map.
Claims20
An initial copy system for remote copy, comprising:
- a plurality of computer systems at a plurality of sites, each of said computer systems includes external devices and storage apparatuses coupled to the external devices, respectively, the storage apparatuses at the plurality of sites being coupled to each other through a communication network,
- wherein data in a first storage apparatus of the storage apparatuses at a first site of the sites being remotely copied into a second storage apparatus of the storage apparatuses at a second site of the sites;
- and
- a third storage apparatus, initially connected to the first storage apparatus at the first site, which is subsequently disconnected from the first storage apparatus and then moved to the second site so as to be connected to the second storage apparatus at the second site, said third storage apparatus being an external storage apparatus with respect to the first and second storage apparatus,
- wherein the first, second and third storage apparatuses each comprises a logical device formed by a plurality of disk drives, external device managing information for defining a configuration of an external storage device, and a control unit,
- wherein the control unit of the first storage apparatus generates a snapshot of the logical device of the first storage apparatus in the logical device of the third storage apparatus and recognizes the logical device in the third storage apparatus as the logical device of the third storage apparatus,
- wherein the control unit in the first storage apparatus generates and manages a bit map indicating difference data between copy target data derived from the snapshot and updated data of copy target data and updates the external device managing information in the first storage apparatus, when the third storage apparatus is disconnected from the first storage apparatus, said third storage apparatus is then subsequently moved to the second site and connected to said second storage apparatus at the second site,
- wherein the control unit in the second storage apparatus recognizes the logical device in the third storage apparatus as a copy target of a remote copy and updates the external device managing information in the second storage apparatus, when the third storage apparatus is connected to the second storage apparatus at the second site after having been disconnected from the first storage apparatus at the first site and moved to the second site so as to be connected to the second storage apparatus at the second site, and
- wherein the control unit of the first storage apparatus controls writing performed by the control unit, of the second storage apparatus on the difference data in the bit map transmitted through the communication network in the logical device recognized by the second storage apparatus so as to accord the data in the second storage apparatus with the data in the first storage apparatus.
6 more elements
An initial copy method for remote copying, wherein a plurality of computer systems are installed at a plurality of sites respectively, each of the computer systems including an external device and a storage apparatus coupled to the external device, the storage apparatuses at the plurality of sites being coupled to each other through a communication network, data in a first storage apparatus of the storage apparatuses at a first site of the sites being remotely copied into a second storage apparatus of the storage apparatuses at a second site of the sites, the method comprising the steps of:
- wherein the first, second and a third storage apparatuses each comprises a logical device formed by a plurality of disk drives, external device managing information for defining a configuration of an external storage device, and a control unit,
- in the control unit in the first storage apparatus at the first site, generating a snapshot of the logical device in the first storage apparatus in the third storage apparatus and recognizing the logical device in the third storage apparatus at first storage apparatus at the first site,
- wherein the third storage apparatus, being initially connected to the first storage apparatus at the first site, is subsequently disconnected from the first storage apparatus and then moved to the second site so as to be connected to the second storage apparatus at the second site, said third storage apparatus being an external storage apparatus with respect to the first and second storage apparatuses,
- in the control unit in the first storage apparatus at the first site, generating and managing a bit map indicating difference data between copy target data derived from the snapshot and updated data of copy target data and updating the external device managing information in the first storage apparatus, when the third storage apparatus is disconnected from the first storage apparatus and said third storage apparatus is subsequently moved to the second site and connected to said second storage apparatus at the second site,
- in the control unit in the second storage apparatus at the second site, recognizing the logical device in the third storage apparatus as a copy target of a remote copy and updating the external device managing information in the second storage apparatus, when the third storage apparatus is connected to the second storage apparatus at the second site after having been disconnected from the first storage apparatus at the first site and moved to the second site so as to be connected to the second storage apparatus at the second site, and
- in the control unit in the first storage apparatus at the first site, controlling writing performed by the control unit of the second storage apparatus based on the difference data in a bit map transmitted through the communication network in the logical device recognized by the second storage apparatus so as to accord the data in the second storage apparatus with the data in the first storage apparatus.
3 more elements
A storage apparatus at a site comprising:
- a logical device configured with a plurality of disk drives;
- external device managing information for defining a configuration of an external storage device;
- and
- a control unit,
- wherein the control unit generates a snapshot of the logical device of the storage apparatus in a logical device in an external storage apparatus independently connected to the storage apparatus at the site, recognizes the logical device in the external storage apparatus as the logical device assigned to the external storage apparatus, manages difference data between copy target data derived from the snapshot and updated data of copy target data, and updates the external device managing information, when the external storage apparatus is disconnected from the storage apparatus, moved to another site and connected to another storage apparatus at the another site,
- wherein the control unit controls writing performed by the control unit of the another storage apparatus in the logical device of the copy target based on the difference data in the bit map transmitted through the communication network in the logical device of a target of copy so as to accord the data in the another storage apparatus with the data in the storage apparatus after the external storage apparatus storing the snapshot is disconnected from the storage apparatus at the site, moved to the another site and connected to the another storage apparatus at the another site, the logical device of the external storage apparatus is recognized as a logical device of a copy target, and the external device managing information in the another storage apparatus is updated.
3 more elements
Dependencies are inferred from the claim text.