# US 2014/0195770 A1 · Serial Attached Storage Drive Virtualization > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0195770 A1 - Document ID: US20140195770A1 - Status: Published application - Kind: A1 - Application number: 13/737,479 - Filed: 2013-01-09 - Published: 2014-07-10 - Earliest claimed: 2013-01-09 - Assignees: Cisco Technology, Inc. - Applicants: Cisco Technology, Inc. - Inventors: Satyanarayana Nishtala - Web page: https://patentgrep.com/patent/US20140195770A1 ## CPC - G06F 3/0644: {Management of space entities, e.g. partitions, extents, pools} - G06F 3/0604: {Improving or facilitating administration, e.g. storage management} - G06F 3/0626: {Reducing size or complexity of storage systems} - G06F 3/0665: {at area level, e.g. provisioning of virtual or logical volumes} - G06F 3/067: {Distributed or networked storage systems, e.g. storage area networks [SAN], network attached storage [NAS]} - 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] - G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N) - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract Techniques are provided for an access device, such as a Serial Attached Small Computer System Interface (SAS) expander, that is in communication with a storage device to subdivide the storage space of the storage device into a plurality of logical storage spaces, where the access device mediates storage and retrieval of data to and from the storage device. The access device maintains a unique identifier assigned to each of the logical storage spaces. Storage and retrieval of data to and from at least one of the logical storage spaces by way of the access device is based on the assigned unique identifier. The storage space may be subdivided using logical block addresses (LBAs) of the storage device without physically partitioning the available storage on the storage device. ## Claims ### Claim 1 A method comprising: at an access device in communication with a storage device, subdividing a storage space of the storage device into a plurality of logical storage spaces, wherein the access device mediates storage and retrieval of data to and from the storage device; maintaining in the access device a unique identifier assigned to each of the logical storage spaces; and storing and retrieving data to and from at least one of the logical storage spaces by way of the access device based on the assigned unique identifier. ### Claim 2 (depends on 1) The method of claim 1, wherein subdividing comprises subdividing the storage space using logical block addresses (LBAs) of the storage device. ### Claim 3 (depends on 1) The method of claim 1, further comprising generating one of the unique identifiers, setting a storage capacity for each logical storage space, and establishing access properties for each logical storage space at one of the access device and a network device. ### Claim 4 (depends on 1) The method of claim 1, further comprising receiving one or more of the unique identifiers, a storage capacity for each logical storage space, and access properties for each logical storage space from a network management device. ### Claim 5 (depends on 1) The method of claim 1, further comprising caching, at the access device, data retrieved from one or more of the logical storage spaces. ### Claim 6 (depends on 1) The method of claim 1, further comprising applying, at the access device, quality of service (QoS) parameters to one or more of the logical storage spaces, wherein storing and retrieving are mediated according to the QoS parameters. ### Claim 7 (depends on 1) The method of claim 1, wherein the access device comprises one of a Serial Attached Small Computer System Interface (SAS) device, network switch, and other device external to the storage device that is associated with a communication path that provides access to the storage device. ### Claim 8 An apparatus comprising: a network interface unit configured to enable network communications over one or more networks; a memory; a processor coupled to the network interface unit and to the memory, wherein the processor is configured to: subdivide a storage space of a storage device into a plurality of logical storage spaces; mediate storage and retrieval of data to and from the storage device; maintain a unique identifier assigned to each of the logical storage spaces; and store and retrieve data to and from at least one of the logical storage spaces by way of the access device based on the assigned unique identifier. ### Claim 9 (depends on 8) The apparatus of claim 8, wherein the processor is configured to subdivide the storage space using logical block addresses (LBAs) of the storage device. ### Claim 10 (depends on 8) The apparatus of claim 8, wherein the processor is further configured to generate one of the unique identifiers, set a storage capacity for each logical storage space, and establish access properties for each logical storage space. ### Claim 11 (depends on 8) The apparatus of claim 8, wherein the processor is further configured to receive one or more of the unique identifiers, a storage capacity for each logical storage space, and access properties for each logical storage space. ### Claim 12 (depends on 8) The apparatus of claim 8, wherein the processor is further configured to cache data retrieved from one or more of the logical storage spaces. ### Claim 13 (depends on 8) The apparatus of claim 8, wherein the processor is further configured to apply quality of service (QoS) parameters to one or more of the logical storage spaces, wherein the processor is configured to store and retrieve according to the QoS parameters. ### Claim 14 (depends on 8) The apparatus of claim 8, wherein the apparatus comprises one of a Serial Attached Small Computer System Interface (SAS) device, network switch, and other device external to the storage device that is associated with a communication path that provides access to the storage device. ### Claim 15 A computer readable medium storing instructions that, when executed by a processor, cause the processor to: subdivide a storage space of a storage device into a plurality of logical storage spaces; mediate storage and retrieval of data to and from the storage device; maintain a unique identifier assigned to each of the logical storage spaces; and store and retrieving data to and from at least one of the logical storage spaces by way of the access device based on the assigned unique identifier. ### Claim 16 (depends on 15) The computer readable storage media of claim 15, further comprising instructions operable to subdivide the storage space using logical block addresses (LBAs) of the storage device. ### Claim 17 (depends on 15) The computer readable storage media of claim 15, further comprising instructions operable to generate one of the unique identifiers, set a storage capacity for each logical storage space, and establish access properties for each logical storage space. ### Claim 18 (depends on 15) The computer readable storage media of claim 15, further comprising instructions operable to receive one or more of the unique identifiers, a storage capacity for each logical storage space, and access properties for each logical storage space. ### Claim 19 (depends on 15) The computer readable storage media of claim 15, further comprising instructions operable to cache data retrieved from one or more of the logical storage spaces. ### Claim 20 (depends on 15) The computer readable storage media of claim 15, further comprising instructions operable to apply quality of service (QoS) parameters to one or more of the logical storage spaces, wherein the instructions operable to store and retrieve comprise instructions operable to store and retrieve according to the QoS parameters.