System and method for emulating SCSI reservations using network file access protocols

• US 7,711,539 B1
• Filed: 08/12/2002
• Issued: 05/04/2010
• Est. Priority Date: 08/12/2002
• Status: Active Grant

• Current Assignee: Network Appliance Incorporated (NetApp, Inc.)
• Original Assignee: NetApp, Inc.
• Inventors: Hawley, Robert, Kimmel, Jeffrey S.
• Primary Examiner(s): Shah; Kamini S
• Assistant Examiner(s): GEBRESILASSIE, KIBROM K
• Application Number:
  US10/217,038
• Time in Patent Office: 2,822 Days
• Field of Search: 703 23- 25, 703/21, 711/4, 711/202, 711/203, 711/112, 711/214, 711/100, 711/11, 709/250, 709/226, 709/330, 709/217, 709/230, 709/223, 709/236, 707/1, 707/205, 707/200, 707/204, 710/8, 710/74, 719/324, 719/326, 719/327
• US Class Current: 703/24
• CPC Class Codes: G06F 3/0622 in relation to access
• CPC Class Codes: G06F 3/0661 Format or protocol conversion arrangements
• CPC Class Codes: G06F 3/067 Distributed or networked storage systems, e.g. storage area networks [SAN], network attached storage [NAS]

Abstract

A system and method for emulating SCSI reservations using network file access protocols is provided. The system and method enable applications or operating systems on a networked computer designed to utilize SCSI reservations on only locally attached storage to also access networked data storage. The emulation occurs transparently to higher levels of operating systems or applications so that the applications or operating systems which are designed to only access locally attached storage may be enabled to access networked storage.

Claims

1. A method for emulating disk-based reservations on a virtual logical disk, comprising:

translating, by a client, a disk-based reservation command into a network file protocol command by mapping the disk-based reservation command to the network file protocol command;

in response to translating, transmitting, by the client, the network file protocol command to a server associated with the virtual logical disk to allow the virtual logical disk to emulate a disk locally attached to the client;

reserving, by the server, the virtual logical disk by storing an identifier within the virtual logical disk wherein the identifier identifies the client as reserving the virtual logical disk;

translating a release command into a release network file protocol command; and

transmitting the release network file protocol command to release the client from reserving the virtual logical disk.

2. The method of claim 1 wherein the disk-based reservations comprises Small Computer System Interface reservations.

4. The method of claim 1 wherein the network file protocol command comprises a Network File System Command.

5. The method of claim 1 wherein the network file protocol command comprises a Common Internet File system command.

6. The method of claim 1 wherein the network file protocol command comprises a Direct Access File System command.

7. The method of claim 1 further comprising modifying, by the network file protocol command, a file access control attribute for storing the identifier of the client on the virtual logical disk.

8. The method of claim 1 wherein the identifier comprises a group identifier of the client.

9. The method of claim 1 wherein the identifier comprises an access control list.

3. A method for emulating disk-based reservations on a virtual logical disk, comprising:

translating, by a client, a disk-based reservation command into a network file protocol command by mapping the disk-based reservation command to the network file protocol command;

in response to translating, transmitting, by the client, the network file protocol command to a server associated with the virtual logical disk to allow the virtual logical disk to emulate a disk locally attached to the client;

reserving, by the server, the virtual logical disk by storing an identifier within the virtual logical disk wherein the identifier identifies the client as reserving the virtual logical disk;

mapping a reset command to a reset network file protocol command; and

transmitting the reset network file protocol command to reset the reservation stored on the virtual logical disk.

10. A method for emulating disk-based reservations on a virtual logical disk, comprising:

converting, by a client, a Small Computer System Interface (SCSI) reservation command into a network file protocol command by mapping the SCSI reservation command to the network file protocol command;

in response to converting, transmitting, by the client, the network file protocol command to a server associated with the virtual logical disk to allow the virtual logical disk to emulate a disk locally attached to the client;

reserving, by the server, the virtual logical disk by storing an identifier within the virtual logical disk wherein the identifier identifies the client as reserving the virtual logical disk;

mapping a SCSI release command to a release network file protocol command; and

transmitting the release network file protocol command to release the client from reserving the virtual logical disk.

11. A method for emulating disk-based reservations on a virtual logical disk, comprising:

converting, by a client, a Small Computer System Interface (SCSI) reservation command into a network file protocol command by mapping the SCSI reservation command to the network file protocol command;

in response to converting, transmitting, by the client, the network file protocol command to a server associated with the virtual logical disk to allow the virtual logical disk to emulate a disk locally attached to the client;

reserving, by the server, the virtual logical disk by storing an identifier within the virtual logical disk wherein the identifier identifies the client as reserving the virtual logical disk;

mapping a SCSI reset command to a reset network file protocol command; and

transmitting the reset network file protocol command to reset the reservation stored on the virtual logical disk.

12. A system, comprising:

a client computer executing a translation function configured to convert a Small Computer System Interface (SCSI) reservation command into a network file protocol command;

a network adapter configured to transmit the network file protocol command to a server associated with a virtual logical disk from the client;

the server configured to reserve the virtual logical disk by storing an identifier within the virtual logical disk, wherein the identifier identifies the client as reserving the virtual logical disk;

the client computer further configured to map a SCSI reset command to a reset network file protocol command; and

the network adapter further configured to transmit the reset network file protocol command to the server for the server to reset the reservation stored on the virtual logical disk.

13. The system of claim 12, wherein the client computer is further configured to map a SCSI release command to a release network file protocol command and the network adapter is further configured to transmit the release network file protocol command to the server for the server to release the client from reserving the virtual logical disk.

14. The system of claim 12, wherein the network file protocol command modifies a file access control attribute for storing the identifier of the client on the virtual logical disk.

15. The system of claim 12, wherein the identifier comprises a group identifier of the client.

16. The system of claim 12, wherein the identifier comprises an access control list.