06748502 is referenced by 44 patents.

A system for providing a data storage service, comprises: a service provider site configured to provide a data storage service; and a user site coupled by a wide area network (WAN) to the service provider site, the user site comprising a local storage having a virtual storage, the virtual storage having a synchronous volume and an asynchronous volume, the local storage configured to immediately transmit to the service provider site data that is written in the synchronous volume, to transmit at a predetermined schedule to the service provider site data that is written in the asynchronous volume, and to read data from the service provider site if the data is not stored in the local storage.

Title
Virtual volume storage
Application Number
9/760344
Publication Number
6748502 (B2)
Application Date
January 12, 2001
Publication Date
June 8, 2004
Inventor
Akira Yamamoto
Cupertino
CA, US
Naoki Watanabe
Sunnyvale
CA, US
Agent
Squire Sanders & Dempsey L
US
Assignee
Hitachi
US
IPC
G06F 13/00
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