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

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.

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.

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.

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.

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.