SHARED NETWORK-AVAILABLE STORAGE THAT PERMITS CONCURRENT DATA ACCESS

• US 20130262615A1
• Filed: 03/11/2013
• Published: 10/03/2013
• Est. Priority Date: 03/30/2012
• Status: Active Grant

• Current Assignee: CommVault Systems Incorporated
• Original Assignee: CommVault Systems Incorporated
• Inventors: Vijayan, Manoj Kumar, Kottomtharayil, Rajiv, Ankireddypalle, Ramachandra Reddy
• Granted Patent: US 9,639,297 B2
• Time in Patent Office: Days
• US Class Current: 709/213
• CPC Class Codes: G06F 3/0604 Improving or facilitating administration, e.g. storage management
• CPC Class Codes: G06F 3/0619 in relation to data integrity, e.g. data losses, bit errors
• CPC Class Codes: G06F 3/0635 by changing the path, e.g. traffic rerouting, path reconfiguration
• CPC Class Codes: G06F 3/065 Replication mechanisms
• CPC Class Codes: G06F 3/067 Distributed or networked storage systems, e.g. storage area networks [SAN], network attached storage [NAS]
• CPC Class Codes: H04L 67/1097 for distributed storage of data in networks, e.g. transport arrangements for network file system [NFS], storage area networks [SAN] or network attached storage [NAS]

Abstract

Techniques for providing shared access to, e.g., a small computer system interface (SCSI) storage device in a computer network include providing an operational mode on SCSI interfaces with a first media agent and a second media agent such that, in response to inquiry messages on the SCSI interfaces, the SCSI storage device appears as a SCSI target device to the first media agent and the second media agent and mapping data operations between the first media agent and the SCSI storage device and the second media agent and the SCSI storage device to logically unique channel numbers for the first media agent and the second media agent to perform data storage operations over their respective SCSI interfaces by concurrently sharing the SCSI storage device.

Claims

1. A method for providing shared access over a fibre channel small computer system interface (SCSI) interface to a storage device in a computer network, comprising:

providing an operational mode on SCSI interfaces with a first media agent and a second media agent such that, in response to inquiry messages on the SCSI interfaces, the storage device appears as a SCSI target device to the first media agent and the second media agent; and

mapping data operations between the first media agent and the storage device and the second media agent and the storage device to logically unique channel numbers for the first media agent and the second media agent to perform data storage operations over their respective SCSI interfaces by concurrently sharing the storage device.

2. The method of claim 1, wherein the operation of providing the operational mode comprises:

configuring a host bus adapter (HBA) at a kernel level to implement a SCSI target mode subsystem; and

initializing, by the SCSI target mode subsystem, the HBA as a SCSI target.

3. The method of claim 2, wherein the operation of configuring the HBA includes:

configuring the HBA to respond to the inquiry messages by reporting a disk vendor identification (ID), wherein the disc vendor ID is selected such that a combination of the disk vendor ID and a host name associated with the HBA uniquely identifies the storage device in the computer network.

4. The method of claim 2, wherein the HBA is operable in a host system and wherein the operation of configuring the HBA at kernel level includes:

providing an in-kernel virtual disk device handler that;

functions as a SCSI device interface to a user level protocol stack executable on the host system; and

functions as a higher layer to the SCSI target mode subsystem.

5. The method of claim 1, further comprising:

providing a deduplication database in the computer network, wherein the deduplication database is configured to communicate with the first media agent and the second media agent over a deduplication interface that is different from the SCSI interfaces.

6. The method of claim 1, further comprising:

adding storage capacity to the storage device; and

making the added storage capacity available to the first media agent and the second media agent without having to provision the added storage capacity on the first media agent and the second media agent.

7. The method of claim 1, wherein the first media agent and the second media agent are implemented using different operating systems.

8. The method of claim 1, wherein the data operations are performed using Universal Datagram protocol (UDP).

9. A computer program product comprising at least one computer-readable medium, having code stored thereon, the code, when executed, causing a processor to provide shared access over a small computer system interface (SCSI) interface to a storage device in a computer network, the method comprising:

causing the storage device to appear as a SCSI target device to a first media agent and a second media agent

wherein the first media agent and the second media agent respond to inquiry messages on SCSI interfaces; and

concurrently sharing the storage device by permitting data operations between the first media agent and the storage device and, and between the second media agent and the storage device,

wherein the first media agent is associated with a first logically unique channel number,

wherein the second media agent is associated with a second logically unique channel number, and

wherein the first media agent and the second media agent to perform data storage operations over respective first and second SCSI interfaces, in part, based on the first and second logically unique channel numbers.

10. The computer program product of claim 9, wherein providing the operational mode comprises:

configuring a host bus adapter (HBA) at a kernel level to implement a SCSI target mode subsystem; and

initializing, by the SCSI target mode subsystem, the HBA as a SCSI target.

11. The computer program product of claim 10, wherein configuring the HBA includes:

configuring the HBA to respond to the inquiry messages by reporting a disk vendor identification (ID), wherein the disc vendor ID is selected such that a combination of the disk vendor ID and a host name associated with the HBA uniquely identifies the storage device in the computer network.

12. The computer program product of claim 10, wherein the HBA is operable in a host system and wherein the operation of configuring the HBA at kernel level includes:

providing an in-kernel virtual disk device handler that;

functions as a SCSI device interface to a user level protocol stack executable on the host system; and

functions as a higher layer to the SCSI target mode subsystem.

13. The computer program product of claim 9, wherein the method further comprises:

providing a deduplication database in the computer network, wherein the deduplication database is configured to communicate with the first media agent and the second media agent over a deduplication interface that is different from the SCSI interfaces.

14. The computer program product of claim 9, wherein the method further comprises:

adding storage capacity to the storage device; and

making the added storage capacity available to the first media agent and the second media agent without having to provision the added storage capacity on the first media agent and the second media agent.

15. The computer program product of claim 9, wherein the first media agent and the second media agent are implemented using different operating systems.

16. The computer program product of claim 9, wherein the data operations are performed using Universal Datagram protocol (UDP).

17. In a computer network system comprising multiple clients and a storage device, a method of sharing the storage device among the multiple clients, the method comprising:

providing a plurality of media agents, each media agent configured for performing data deduplication and storage operations for a distinct subset of the multiple clients; and

,

operating a storage server configured to control access by multiple media agents to the storage device such that the multiple media agents are able to perform read/write operations with the storage device using their respective interfaces that can be configured to operate independent of each other and concurrently with each other.

18. The method of claim 17, further comprising:

providing, by the storage server, a mapping between channel numbers used by multiple media agents for data operations over the respective interfaces and corresponding channel numbers over a local interface between the storage server and the storage device, and wherein the respective interfaces are SCSI interfaces.

19. A computer network system comprising multiple clients and a storage device, comprising:

multiple media agents, each media agent configured for performing data deduplication and storage operations for a distinct subset of the multiple clients; and

a storage server configured to control access by the multiple media agents to the storage device

wherein the multiple media agents are configured to perform read/write operations with the storage device using respective interfaces, and

wherein the respective interfaces are configurable to operate independent of each other and concurrently with each other.

20. The system of claim 19, wherein the storage served is further configured to:

provide a mapping between channel numbers used by multiple media agents for data operations over the respective interfaces and corresponding channel numbers over a local interface between the storage server and the storage device, and wherein the respective interfaces are SCSI interfaces.