Storage system group

Patent metadata

Field	Value
Publication number	US-9164941-B2
Application number	US-19091608-A
Country	US
Kind code	B2
Filing date	Aug 13, 2008
Priority date	Oct 24, 2007
Publication date	Oct 20, 2015
Grant date	Oct 20, 2015

Abstract

A first storage system comprises a first logical volume, and a first controller that has a first memory. A second storage system comprises a second physical storage device that constitutes the basis of a second logical volume and a journal area, and a second controller that has a second memory. At least the first memory stores a write unit size, which is the size of a write data element. The journal area is a storage area in which is stored a journal data element, which is a data element that is stored in any block of a plurality of blocks configuring the first and/or second logical volume, or a data element that is written to this block. The size of the journal data element, and the size of the respective blocks that are managed as the respective components of the first and second logical volumes are the write unit size.

First claim

What is claimed is:

1. A storage system group, comprising:
a first storage system; and
a second storage system coupled to the first storage system,
wherein the first storage system comprises:
a plurality of first physical storage devices,
a front interface including a memory,
a cache memory, and
a controller configured to provide a storage pool by at least one of the plurality of first storage devices and to allocate a storage area from the storage pool to a virtual volume dynamically,
wherein the controller is configured to:
manage a plurality of second physical storage devices in the second storage system as external devices;
provide a primary volume by the at least one of the first physical storage devices, in which the primary volume stores data sent from a host computer;
provide a secondary volume by the at least one of the second physical storage devices in the second storage system, in which the secondary volume stores a copy of data stored in the primary volume;
manage a third volume which is the virtual volume provided by the storage pool, in which the third volume is a designated generation of the primary volume;
manage a journal association area provided by the storage pool, in which the journal association area stores online update difference data which is a set of journal data elements stored after a last defined generation (N), where N is the most recent generation, and inter-generational difference data which is a set of journal data elements stored between the generation (N) and a generation (N−1) of the primary volume, and
manage the primary volume divided into a plurality of data blocks,

wherein when the front interface receives a write command and a write data element from the host computer, in which a size of the write data element is one data block, the front interface being configured to write the write data element to the memory and transfer the write command to the controller,
wherein the controller is further configured to:
reserve a first slot and a second slot from the cache memory in response to reception of the write command from the front interface;
write the write data element stored in the memory, to the first slot and the second slot; and
copy the write data element from the first slot to the primary volume, and from the second slot to the association journal area.

2. The storage system group according to claim 1 , wherein the journal association area is not provided to the host computer.

3. The storage system group according to claim 2 , wherein the journal association area is configured to further include a difference bitmap and to manage a set of the difference bitmap and the inter-generational difference data on a generation basis, a generation being a certain point of time of the primary volume.

4. The storage system group according to claim 3 , wherein if two or more of the journal data elements of the plurality of inter-generational difference data are detected in a process of merging a plurality of generations of inter-generational difference data, the controller is configured to store one of the duplicated journal data elements.

Assignees

• Eguchi Yoshiaki
• Yamamoto Akira
• Yamamoto Yasutomo
• Kitamura Manabu
• Satoyama Ai
• Hitachi Ltd

Inventors

• Eguchi Yoshiaki
• Yamamoto Akira
• Yamamoto Yasutomo
• Kitamura Manabu
• Satoyama Ai

Classifications

• G06F11/2071

  using a plurality of controllers · CPC title

• G06F11/1464

  for networked environments · CPC title

• G06F11/1469

  Backup restoration techniques · CPC title

• G06F13/387 Primary

  for adaptation of different data processing systems to different peripheral devices, e.g. protocol converters for incompatible systems, open system · CPC title

• G06F11/2074

  Asynchronous techniques · CPC title