Assimilation of foreign LUNS into a network storage system

A method comprising:

• in a network storage server, defining a plurality of regions to contain data, the plurality of regions including a plurality of logical extents, wherein a plurality of slabs are allocated to the plurality of regions, wherein allocated to each said logical extent is at least a portion of one or more slabs allocated to a region that includes said logical extent, at least some of the slabs being defined each as a set of blocks in one or more physical storage devices;
• in the network storage server, defining at least a portion of a first slab, of the plurality of slabs, to represent a portion of a foreign logical unit (LUN), wherein the first slab corresponds to a sequential set of addresses of the foreign LUN, wherein a device associated with the foreign LUN is not manufactured by a manufacturer of the network storage server and the device associated with the foreign LUN is not specifically designed for use with the network storage server, and wherein the foreign LUN is maintained in a read-only region;
• in the network storage server, allocating said at least a portion of the first slab to a first logical extent of the plurality of logical extents, the first logical extent being included within a first region of the plurality of regions;
• storing at least one write-back change to the foreign LUN in a native solid state storage separate from the foreign LUN;
• storing at least one snapshot of at least a portion of the foreign LUN in a native hard disk storage separate from the foreign LUN;
• and
• in the network storage server, maintaining a plurality of volumes as logical containers of data, each of the volumes including one or more of the logical extents from one or more of the regions, wherein layouts of the logical extents within the regions are not visible to the plurality of volumes.

A network storage server comprising:

• a network adapter through which to communicate with a plurality of storage clients via a network;
• a storage adapter through which to access a set of physical storage devices;
• and
• a computer readable storage medium comprising instructions that, when executed, cause a processor to execute operations including:
• defining a plurality of regions to contain data, the plurality of regions including a plurality logical extents;
• defining at least a portion of a first slab as a portion of a foreign logical unit (LUN), and allocating said at least a portion of the first slab to a first logical extent of the plurality of logical extents, the first logical extent being included within a first region of the plurality of regions, wherein a device associated with the foreign LUN is not manufactured by a manufacturer of the network storage server and the device associated with the foreign LUN is not specifically designed for use with the network storage server;
• storing at least one write-back change to the foreign LUN in a native storage separate from the foreign LUN;
• and
• maintaining a plurality of volumes as logical containers of data, each of the volumes including one or more of the logical extents from one or more of the regions, wherein layouts of the logical extents within the regions are not visible to the plurality of volumes.

A storage system node for use in a cluster of storage system nodes, the storage system node comprising:

• an N-module configured to provide network communication services to communicate with a storage host over a network, the N-module further configured to communicate with a separate D-module in each of the plurality of storage server nodes in the cluster;
• and
• a D-module operatively coupled to the N-module and configured to provide storage and retrieval of data objects in a nonvolatile mass storage facility which includes a plurality of physical storage devices, the D-module configured to:
• define a plurality of regions to contain data, the plurality of regions including a plurality of logical extents, wherein a plurality of slabs are allocated to the plurality of regions, wherein allocated to each said logical extent is at least a portion of one or more slabs allocated to a region that includes said logical extent, at least some of the slabs being defined each as a set of blocks in one or more physical storage devices;
• define at least a portion of a first slab, of the plurality of slabs, to represent a portion of a foreign logical unit (LUN), wherein the first slab corresponds to a sequential set of addresses of the foreign LUN, wherein a device associated with the foreign LUN is not manufactured by a manufacturer of the storage system node and the device associated with the foreign LUN is not specifically designed for use with the storage system node;
• allocate at least a portion of the first slab to a first logical extent of the plurality of logical extents, the first logical extent being included within a first region of the plurality of regions;
• store at least one write-back change to the foreign LUN in a native storage separate from the foreign LUN;
• and
• maintain a plurality of volumes as logical containers of data, each of the volumes including one or more of the logical extents from one or more of the regions, wherein layouts of the logical extents within the regions are not visible to the plurality of volumes.