US 2004/0073831 A1Published application

Remote data mirroring

AssigneeEMC Corporation

InventorsMoshe Yanai, Natan Vishlitzky, Bruno Alterescu, Daniel Castel, Gadi Shklarsky, Yuval Ofek

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Abstract

Two data storage systems are interconnected by a data link for remote mirroring of data. Each volume of data is configured as local, primary in a remotely mirrored volume pair, or secondary in a remotely mirrored volume pair. Normally, a host computer directly accesses either a local or a primary volume, and data written to a primary volume is automatically sent over the link to a corresponding secondary volume. Each remotely mirrored volume pair can operate in a selected synchronization mode including synchronous, semi-synchronous, adaptive copy—remote write pending, and adaptive copy—disk. Direct write access to a secondary volume is denied if a “sync required” attribute is set for the volume and the volume is not synchronized.

Claims12

Dependent claims

A system for automatically providing remote copy data storage, said system comprising:

a host computer;
a first data storage system including at least a first data storage system controller and at least one data storage device, said first data storage system being coupled to said host computer for storing data to be accessed by at least said host computer;
a second data storage system including at least a second data storage system controller and at least one data storage device, said second data storage system being remotely coupled to said first data storage system for copying of said data to said second data storage system controller;
and
said first data storage system controller coordinating and controlling the copying of said data to said second data storage system controller wherein said first data storage system maintains an index, said index including at least a first indicator providing an indication of whether a predetermined data element stored on said first data storage system is valid, a second indicator providing an indication of whether said predetermined data element stored on said second data storage system is valid, a third indicator providing an indication of whether a write is pending to said predetermined data element stored on said first data storage system, and at least a fourth indicator providing an indication of whether a write is pending to said predetermined data element stored in said second data storage system.

2 more elements

A data storage system for automatically providing remote data copying to remote data storage, said data storage system comprising:

primary data storage for storing a primary copy of data;
and
a data storage controller for controlling storage of data in said primary data storage and transmission of data over a link from said data storage system to said remote data storage to store a secondary copy of the data in said remote data storage;
wherein said data storage system maintains an index, said index including at least a first indicator providing an indication of whether a predetermined data element stored on said data storage system is valid, a second indicator providing an indication of whether said predetermined data element stored in said remote data storage is valid, a third indicator providing an indication of whether a write is pending to said predetermined data element stored on said data storage system, and at least a fourth indicator providing an indication of whether a write is pending to said predetermined data element stored in said remote data storage.

1 more element

A method of operating a data storage system for automatically providing remote data copying to remote data storage, said data storage system having primary data storage for storing a primary copy of data, and a data storage controller for controlling storage of data in said primary data storage and transmission of data over a link from said data storage system to said remote data storage to store a secondary copy of the data in said remote data storage, said method comprising:

maintaining, in storage of said data storage system, a first indicator providing an indication of whether a predetermined data element stored on said data storage system is valid;
maintaining, in said data storage system, a second indicator providing an indication of whether said predetermined data element stored in said remote data storage is valid;
maintaining, in said data storage system, a third indicator providing an indication of whether a write is pending to said predetermined data element stored on said data storage system;
and
maintaining, in said data storage system, a fourth indicator providing an indication of whether a write is pending to said predetermined data element stored in said remote data storage.

2 more elements

Dependencies are inferred from the claim text.

Facts

Application: 10/330,715Filed 27 Dec 2002
Priority: 23 Apr 1993
Published: 15 Apr 2004
Term ends: Not estimatedThe source records don’t support an estimate.

Classification24 codes

G06F 11/2071
By mirroring: using a plurality of controllers
G06F 3/0601
Digital input from, or digital output to, record carriers , e.g. RAID, emulated record carriers or networked record carriers: interfaces specially…
G06F 3/0608
Specifically adapted to achieve a particular effect: saving storage space on storage systems
G06F 3/061
Specifically adapted to achieve a particular effect: improving I/O performance

Family

Application08/052,039Continuation in part · filed 23 Apr 1993
Application08/654,511Continuation · filed 28 May 1996
Application08/654,511Continuation in part · filed 28 May 1996
Application09/061,708Division · filed 17 Apr 1998
Application09/061,708Continuation · filed 17 Apr 1998
Application09/709,814Continuation · filed 10 Nov 2000
Application09/709,814Division · filed 10 Nov 2000
Application10/330,715Continuation · filed 27 Dec 2002
US 5,544,347 ARelated patent
US 5,742,792 ARelated patent
US 6,173,377 B2Related patent
US 6,502,205 B1Related patent
US 7,055,059 B2Related patent
US 2004/0073831 A1This patent

From the US filing history. Foreign family members aren’t listed.