Virtualized storage devices for network disk mirroring applications

• US 6,389,459 B1
• Filed: 12/09/1998
• Issued: 05/14/2002
• Est. Priority Date: 12/09/1998
• Status: Expired due to Term

• Current Assignee: Teradata US, Inc. (Teradata Corporation)
• Original Assignee: NCR Corporation (NCR Voyix Corporation)
• Inventors: McDowell, Steven R.
• Primary Examiner(s): Maung, Zarni
• Application Number:
  US09/207,934
• Time in Patent Office: 1,252 Days
• Field of Search: 709/208, 709/216, 714/13, 714/4, 714/10, 714/6, 714/1, 707/10, 711/114, 711/100
• US Class Current: 709/216
• CPC Class Codes: G06F 11/2035 without idle spare hardware
• CPC Class Codes: G06F 11/2069 Management of state, configuration or failover
• CPC Class Codes: G06F 11/2071 using a plurality of controllers
• CPC Class Codes: G06F 11/2079 Bidirectional techniques

Abstract

A system for mirroring data and disk drive device state over a network between a source computer including a first non-shared disk drive storage device and a target computer including a second non-shared disk drive storage device. The system includes layered software drivers installed within the source computer above the device driver for the first disk drive storage device for capturing and examining write requests directed to the first disk drive storage device, and transmitting the write request and extracted device state information to the target computer. Software drivers installed within the target computer above the device driver for the second disk drive storage device direct the received write requests to the second disk drive storage device, and the received device state information to volatile storage within the target computer.

Claims

1. A computer system, comprising:

a first server computer including a first storage volume;

a second server computer including a second storage volume;

a communication network connecting said first and second server computers; and

a network operating system implemented within said first and second server computers which supports layered drivers;

said first server computer including;

a file system mirror driver for capturing write requests directed to said first storage volume and transmitting the write requests to said second server computer; and

a state filter driver for examining device commands directed to said first storage volume, determining a device state for the first storage volume, and transmitting said device state to said second server computer; and

said second server computer including;

a storage device;

a file system mirror driver for receiving the write requests from said first server computer and directing the write requests to said second storage volume; and

a state mirror driver for receiving said device state from said first server computer and storing said device state in said storage device.

2. The computer system in accordance with claim 1, wherein:

said communications network connecting said first and second server computers comprises a clustered computer system.

3. The computer system in accordance with claim 2, wherein:

said network operating system comprises Microsoft Corporation'"'"'s Windows NT operating system.

4. The computer system in accordance with claim 1, wherein:

said first storage volume comprises a first disk drive; and

said second storage volume comprises a second disk drive.

5. A computer system, comprising:

a first server computer including a first non-mirrored storage volume and a first mirrored storage volume;

a second server computer including a second non-mirrored storage volume and a second mirrored storage volume;

a communication network connecting said first and second server computers; and

a network operating system implemented within said first and second server computers which supports layered drivers;

said first server computer including;

a file system mirror driver for capturing write requests directed to said first mirrored storage volume and transmitting the write requests to said second server computer; and

a state filter driver for examining device commands directed to said first storage volume, determining a device state for the first storage volume, and transmitting said device state to said second server computer; and

said second server computer including;

a storage device;

a file system mirror driver for receiving the write requests from said first server computer and directing the write requests to said second mirrored storage volume; and

a state mirror driver for receiving said device state from said first server computer and storing said device state in said storage device.

6. A mirrored storage system for a clustered computer system, said clustered computer system including a first server computer including a first storage volume;

a second server computer including a second storage volume;

a communication network connecting said first and second server computers; and

a network operating system implemented within said first and second server computers which supports layered drivers;

said mirrored storage system comprising;

within said first server computer;

a file system mirror driver for capturing write requests directed to said first storage volume and transmitting the write requests to said second server computer; and

a state filter driver for examining device commands directed to said first storage volume, determining a device state for the first storage volume, and transmitting said device state to said second server computer;

within said second server computer;

a storage device;

a file system mirror driver for receiving the write requests from said first server computer and directing the write requests to said second storage volume; and

a state mirror driver for receiving said device state from said first server computer and storing said device state in said storage device.

7. A method for mirroring disk volumes over a networked computer system, said networked computer system including a primary server computer including a primary storage volume;

a secondary server computer including a secondary storage volume;

a communication network connecting said primary and secondary server computers; and

a network operating system implemented within said primary and secondary server computers which supports layered drivers;

said method comprising the steps of;

capturing write requests directed to said primary storage volume within said primary server computer and transmitting the write requests to said secondary storage volume within said secondary server computer;

examining device commands directed to said primary storage volume and transmitting a device state to said secondary server computer; and

storing said device state in a storage device within said secondary server computer.