Storage system and data management method
AssigneeHitachi, Ltd.
InventorsKazuaki Shono, Yusuke Hirakawa, Katsuhiro Okumoto
Life of this patent
Estimating the term…
Abstract
On the first storage device side, when data is written in a first volume, a journal of such data is transmitted to a second storage device; on the second storage device side, a snapshot of a second volume and the respective journals are stored; on the second storage device side, the first volume is rebuilt at a rebuilding time according to a rebuilding order; on the second storage device side, data of an address rewritten from the rebuilding time onward is transmitted as difference data to the first storage device; and on the first storage device side, the first volume is rebuilt at the rebuilding time based on the difference data.
Claims13
A storage system having a first storage device connected to a host system and which provides a first volume for storing data transmitted from said host system, and a second storage device connected to said first storage device and which provides a second volume for storing backup data of said first volume;
- wherein said first storage device comprises a journal creation unit for creating a journal representing the written contents when said data is written in said first volume;
- said second storage device comprises:
- a snapshot acquisition unit for acquiring a snapshot of said second volume in a prescribed timing;
- a memory device for storing each of said journals transmitted from said first storage device and said snapshot acquired with said snapshot acquisition unit;
- a volume rebuilding unit for rebuilding, upon using the corresponding said journal and said snapshot stored in said memory device in accordance with the rebuilding order designating the rebuilding time provided from said host system, said first volume at said rebuilding time;
- and
- a difference data output unit for outputting said data of an address rewritten from said rebuilding time onward among said rebuilt data stored in said first volume at said rebuilding time as difference data;
- and
- said first storage device rebuilds said first volume at said rebuilding time based on said difference data transmitted from said second storage device.
A data management method in a storage system having a first storage device connected to a host system and which provides a first volume for storing data transmitted from said host system, and a second storage device connected to said first storage device and which provides a second volume for storing backup data of said first volume, comprising:
- a first step of creating, on said first storage device side, a journal representing the written contents when said data is written in said first volume and transmitting this to said second storage device, and, on said second storage device side, acquiring a snapshot of said second volume in a prescribed timing and storing said snapshot and each of said journals transmitted from said first storage device;
- a second step of rebuilding, on said second storage device side, upon using the corresponding said journal and said snapshot stored in said memory device in accordance with the rebuilding order designating the rebuilding time provided from said host system, said first volume at said rebuilding time;
- a third step of transmitting, on said second storage device side, said data of an address rewritten from said rebuilding time onward among said rebuilt data stored in said first volume at said rebuilding time as difference data to said first storage device;
- and
- a fourth step of rebuilding, on said first storage device side, said first volume at said rebuilding time based on said difference data.
A storage system having a first storage device connected to a host system and comprising a first volume for storing data transmitted from said host system, and a second storage device connected to said first storage device and comprising a second volume for storing backup data of said first volume;
- wherein said first storage device comprises a journal representing the written contents when said data is written in said first volume, and a transmission unit for transmitting said journal to said second storage device;
- said second storage device comprises:
- a snapshot acquisition unit for acquiring a snapshot of said second volume in a prescribed timing;
- a memory device for storing said journal transmitted from said first storage device and said snapshot acquired with said snapshot acquisition unit;
- a rebuilding unit for rebuilding, upon using said snapshot stored in said memory device in accordance with the rebuilding order designating the rebuilding time provided from said host system and said journal stored in said memory and associated with said rebuilding order in accordance with said rebuilding order, the data content stored in said first volume at said rebuilding time;
- and
- a difference data output unit for transmitting said data corresponding to an address written from said host system after said rebuilding time among said data content as difference data to said first storage device;
- and
- said first storage device rebuilds the data content stored in said first volume at said rebuilding time based on said difference data transmitted from said second storage device, and said first volume.
Dependencies are inferred from the claim text.