System and method for providing availability using volume server sets in a storage environment employing distributed block virtualization

• US 8,046,446 B1
• Filed: 10/18/2004
• Issued: 10/25/2011
• Est. Priority Date: 10/18/2004
• Status: Expired due to Fees

• Current Assignee: Veritas Technologies, LLC (Whitehouse Group Ltd.)
• Original Assignee: Symantec Operating Corporation (NortonLifeLock Inc.)
• Inventors: Kong, Chio Fai Aglaia, Sharma, Gopal, Rao, Santosh, Baird, Robert, Karr, Ronald S.
• Primary Examiner(s): Pwu; Jeffrey
• Assistant Examiner(s): Khajuria; Shripal
• Application Number:
  US10/967,902
• Time in Patent Office: 2,563 Days
• Field of Search: 709/223
• US Class Current: 709/223
• 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

A system for ensuring availability using volume server sets in a storage environment employing distributed block virtualization includes a plurality of volume servers, one or more volume clients, one or more physical block devices and a volume server manager. The volume server manager may be configured to designate the plurality of volume servers as a volume server set with an associated volume server set management policy, and to verify each volume server in the volume server set has access to storage within each block device. In addition, the volume server manager may be configured to designate a first volume server of the volume server set to aggregate storage within the block devices into a logical volume, to make the logical volume accessible to the volume clients, and to share configuration information about the volume with the other volume servers of the volume server set.

Claims

1. A system comprising:

one or more volume clients;

one or more physical block devices coupled to the volume clients via a network; and

a plurality of volume servers separate from and interposed between said clients and said block devices, wherein said volume servers are coupled to the block devices via a network;

a volume server manager coupled to said plurality of volume servers via a network, wherein the volume server manager is configured to;

designate the plurality of volume servers as a volume server set with an associated volume server set management policy;

verify that storage in each of the one or more physical block devices is accessible to each volume server in the volume server set in accordance with the volume server set management policy; and

designate a first volume server of the volume server set to;

aggregate storage in the one or more physical block devices into a logical volume;

make the logical volume accessible to the one or more volume clients; and

make configuration information for the logical volume accessible to each other volume server of the volume server set;

designate the first volume server of the volume server set as an active volume server, wherein the active volume server is configured to perform virtualization functions for the volume server set;

wherein in response to a failure, the volume server manager is configured to designate a second volume server as an active volume server; and

wherein the second volume server is configured to disallow access to the logical volume from the first volume server upon a detection of the failure.

2. The system as recited in claim 1, further comprising a plurality of nodes configured as a cluster, wherein the volume server manager is configured to execute at a first node of the cluster, and wherein the volume server manager is configured to migrate from the first node of the cluster to a second node of the cluster in accordance with a volume server manager clustering policy.

3. The system as recited in claim 1, further comprising a first and a second computer host, wherein a first instance of the volume server manager is configured to execute at the first computer host, and a second instance of the volume server manager is configured to execute at the second computer host, and wherein the first and second instances are configured to coordinate an implementation of the volume server set management policy.

4. The system as recited in claim 1, wherein the volume server set management policy includes a failover policy, wherein the failover policy includes at least one of:

a standby failover policy, a load-based failover policy, an external failover policy, and a no-failover policy.

5. The system as recited in claim 1, wherein the volume server manager is further configured to:

monitor the current active volume server;

wherein in response to detecting a failure of the active volume server, the volume server manager is configured to designate the second volume server of the plurality of volume servers as an active volume server; and

wherein the second volume server acting as active volume server is configured to disallow access to the logical volume from the first volume server.

6. The system as recited in claim 5, wherein the volume server set management policy includes a connectivity policy, wherein connectivity between a volume server and a physical block device is established in accordance with the connectivity policy using at least one of:

automated discovery of devices, modification of zoning information, modification of LUN masking information, configuration of an Internet Storage Name Service (iSNS) server, and distribution of iSCSI access keys.

7. The system as recited in claim 5, wherein the connectivity policy includes at least one of:

an automatic connectivity policy, a manual connectivity policy and a workflow-managed connectivity policy.

8. The system as recited in claim 1, wherein the first volume server is configured to periodically verify accessibility to each of the one or more physical block devices.

9. The system as recited in claim 1, wherein the volume server set management policy includes a load-balancing policy.

10. The system as recited in claim 1, wherein the volume server manager is further configured to associate a quality-of-service (QOS) requirement with the volume server set.

11. The system as recited in claim 10, wherein the QOS requirement includes a requirement for a specified minimum number of alternate paths to a storage device.

12. The system as recited in claim 10, wherein the volume server manager is further configured to verify that a current configuration of the volume server set meets the QOS requirement.

13. The system as recited in claim 10, wherein the volume server manager is further configured to verify that a proposed configuration of the volume server set meets the QOS requirement.

14. The system as recited in claim 1, wherein the configuration information includes an identification of the one or more volume clients.

15. The system as recited in claim 1, wherein the configuration information is stored in a configuration database accessible to each volume server of the plurality of volume servers.

16. The system as recited in claim 1, wherein a notification of the designation of the second volume server as an active volume server is sent to the one or more volume clients by the second volume server or by the volume server manager.

17. The system as recited in claim 1, wherein the second volume server is configured to disallow access to the logical volume from an additional volume client without a communication between the second volume server and the additional volume client.

18. The system as recited in claim 17, wherein the additional volume client is provided access to the logical volume by the second volume server using at least one of:

zoning, LUN masking, SCSI-3 persistent group reservations, and security tokens.

19. A system comprising:

one or more volume clients;

one or more physical block devices coupled to the volume clients via a network; and

a plurality of volume servers separate from and interposed between said clients and said block devices, wherein said volume servers are coupled to the block devices via a network;

a volume server manager coupled to said plurality of volume servers via a network,

wherein the volume server manager is configured to;

designate the plurality of volume servers as a volume server set with an associated volume server set management policy;

verify that storage in each of the plurality of physical block devices is accessible to each volume server in the volume server set; and

designate a first volume server of the volume server set to;

aggregate storage in a first device group comprising a first subset of the plurality of physical block devices into a first logical volume;

aggregate storage in a second device group comprising a second subset of the plurality of physical block devices into a second logical volume;

make the first and second logical volumes accessible to the one or more volume clients; and

make configuration information for the first and second logical volumes accessible to each other volume server of the volume server set;

designate the first volume server of the volume server set as an active volume server, wherein the active volume server is configured to perform virtualization functions for the volume server set;

wherein the volume server set management policy includes a first failover policy for the first device group and a second failover policy for the second device group, and the first failover policy differs from the second failover policy;

wherein in response to a failure, the volume server manager is configured to designate a second volume server as an active volume server; and

wherein the second volume server is configured to disallow access to the first logical volume from the first volume server upon a detection of the failure.

20. The system as recited in claim 19, wherein the volume server manager is further configured to designate the second volume server as an active volume server for the second logical volume in response to at least one of:

a detection of a load imbalance, an application request, or an administrator request.

21. A system comprising:

one or more volume clients;

one or more physical block devices coupled to the volume clients via a network; and

a plurality of volume servers separate from and interposed between said clients and said block devices, wherein said volume servers are coupled to the block devices via a network;

a volume server manager coupled to said plurality of volume servers via a network, wherein the volume server manager is configured to;

designate the plurality of volume servers as a volume server set with an associated volume server set management policy;

verify that storage in each of the plurality of physical block devices is accessible to each volume server in the volume server set;

designate a first volume server of the volume server set to;

aggregate storage in a first subset of the plurality of physical block devices into a first logical volume;

make the first logical volume accessible to the one or more volume clients; and

make configuration information for the first logical volume accessible to each other volume server of the volume server set; and

designate a second volume server of the volume server set to;

aggregate storage in a second subset of the plurality of physical block devices into a second logical volume;

make the second logical volume accessible to the one or more volume clients; and

make configuration information for the second logical volume accessible to each other volume server of the volume server set;

designate the first volume server of the volume server set as an active volume server, wherein the active volume server is configured to perform virtualization functions for the volume server set;

wherein in response to a failure, the volume server manager is configured to designate a second volume server as an active volume server; and

wherein the second volume server is configured to disallow access to the logical volume from the first volume server upon a detection of the failure.

22. A system comprising:

one or more volume clients;

one or more physical block devices coupled to the volume clients via a network; and

a plurality of volume servers separate from and interposed between said clients and said block devices, wherein said volume servers are coupled to the block devices via a network;

a volume server manager coupled to said plurality of volume servers via a network, wherein the volume server manager is configured to;

designate a first subset of the plurality of volume servers as a first volume server set with an associated first volume server set management policy, and a second subset of the plurality of volume servers as a second volume server set with an associated second volume server set management policy;

verify that storage in a first device group comprising a first subset of the plurality of physical block devices is accessible to each volume server in the first volume server set;

verify that storage in a second device group comprising a second subset of the plurality of physical block devices is accessible to each volume server in the second volume server set;

designate a first volume server from the first volume server set to;

aggregate storage in the first device group into a first logical volume;

make the first logical volume accessible to the one or more volume clients; and

make configuration information for the first logical volume accessible to each other volume server of the first volume server set; and

designate the first volume server of the volume server set as an active volume server, wherein the active volume server is configured to perform virtualization functions for the volume server set;

designate a second volume server from the second volume server set to;

aggregate storage in the second device group into a second logical volume;

make the second logical volume accessible to the one or more volume clients; and

make configuration information for the second logical volume accessible to each other volume server of the second volume server set;

wherein the first volume server set management policy differs from the second volume server set management policy;

wherein in response to a failure, the volume server manager is configured to designate a second volume server as an active volume server; and

wherein the second volume server is configured to disallow access to the logical volume from the first volume server upon a detection of the failure.

23. The system as recited in claim 22, wherein the volume server manager is further configured to migrate the first volume server from the first volume server set to the second volume server set in response to a configuration command.

24. A method comprising:

designating a plurality of volume servers as a volume server set with an associated volume server set management policy;

verifying that storage in each of one or more physical block devices is accessible to each volume server in the volume server set in accordance with the volume server set management policy, wherein said plurality of volume servers is separate from and interposed between one or more clients and said block devices, wherein said volume servers are coupled to the physical block devices via a network; and

designating a first volume server of the plurality of volume servers to;

aggregate storage in the one or more physical block devices into a logical volume;

make configuration information for the logical volume accessible to each other volume server in the volume server set; and

make the logical volume accessible to one or more volume clients

designating the first volume server of the volume server set as an active volume server, wherein the active volume server is configured to perform virtualization functions for the volume server set;

wherein in response to a failure, the volume server manager designating a second volume server as an active volume server; and

wherein the second volume server is configured to disallow access to the logical volume from the first volume server upon a detection of the failure.

25. The method as recited in claim 24, wherein the volume server set management policy includes a failover policy.

26. The method as recited in claim 24, wherein the volume server set management policy includes a connectivity policy.

27. The method as recited in claim 24, wherein the volume server set management policy includes a load balance policy.

28. A non-transitory computer readable storage medium comprising program instructions, wherein the program instructions are executable to:

designate a plurality of volume servers as a volume server set with an associated volume server set management policy;

verify that storage in each of one or more physical block devices is accessible to each volume server in the volume server set in accordance with the volume server set management policy, wherein said plurality of volume servers is separate from and interposed between one or more clients and said block devices, wherein said volume servers are coupled to the physical block devices via a network; and

designate a first volume server of the plurality of volume servers to;

aggregate storage in the one or more physical block devices into a logical volume;

make configuration information for the logical volume accessible to each other volume server in the volume server set; and

make the logical volume accessible to one or more volume clients;

designate the first volume server of the volume server set as an active volume server, wherein the active volume server is configured to perform virtualization functions for the volume server set;

wherein in response to a failure, the volume server manager is configured to designate a second volume server as an active volume server; and

wherein the second volume server is configured to disallow access to the logical volume from the first volume server upon a detection of the failure.

29. The non-transitory computer readable storage medium as recited in claim 28, wherein the volume server set management policy includes a failover policy.

30. The non-transitory computer readable storage medium as recited in claim 28, wherein the volume server set management policy includes a connectivity policy.

31. The non-transitory computer readable storage medium as recited in claim 28, wherein the volume server set management policy includes a load balance policy.