# US 2014/0195698 A1 · Non-disruptive configuration of a virtualization cotroller in a data storage system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0195698 A1 - Document ID: US20140195698A1 - Status: Published application - Kind: A1 - Application number: 14/201,745 - Filed: 2014-03-07 - Published: 2014-07-10 - Earliest claimed: 2011-08-31 - Assignees: International Business Machines Corporation - Applicants: International Business Machines Corporation - Inventors: Ashish Chaurasia; Subhojit Roy - Web page: https://patentgrep.com/patent/US20140195698A1 ## CPC - G06F 3/0619: {in relation to data integrity, e.g. data losses, bit errors} - G06F 3/061: {Improving I/O performance} - G06F 3/0617: {in relation to availability} - G06F 3/0632: {by initialisation or re-initialisation of storage systems} - G06F 3/0635: {by changing the path, e.g. traffic rerouting, path reconfiguration} - G06F 3/0637: {Permissions} - 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]} - G06F 3/0689: {Disk arrays, e.g. RAID, JBOD} - G06F 12/0866: for peripheral storage systems, e.g. disk cache - G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N) ## Abstract Embodiments of the invention relate to configuring a virtualization controller in SAN data storage system without disrupting I/O operations. One aspect of the invention concerns a method that comprises establishing a first data path between a host and a storage controller in the same communication zone wherein the storage controller comprises storage devices for storing data; adding a virtualization controller to the zone wherein the virtualization controller maps the storage devices to virtual volumes and establishes a second data path between the host and the storage devices through the virtual volumes; removing the first data path in response to the host detecting the second data path; and performing I/O operations between the host and the storage devices through the second data path. ## Claims ### Claim 1 A method for configuring a data storage system, comprising: establishing a first data path between a host and a storage controller that interfaces with the host and a plurality of storage devices for storing data, wherein the host accesses the disks through the storage controller, wherein the host and the disks are in a communication zone; adding a virtualization controller to map the storage devices to a plurality of virtual volumes; establishing a second data path between the host and the storage devices through the virtual volumes, wherein the host recognizes the virtual volumes as an alternate data path to the first data path between the hosts and the storage devices; removing the first data path between the host and the storage controller in response to establishing the second data path, wherein the virtualization controller is configured without disrupting I/O operations between the host and the disks; and performing I/O operations between the host and the disks through the second data path and the virtualization controller. ### Claim 2 (depends on 1) The method of claim 1, wherein the storage devices are coupled to the storage controller, and the storage controller is coupled to the host. ### Claim 3 (depends on 1) The method of claim 1, further comprising disabling data caching in the virtualization controller during the configuration. ### Claim 4 (depends on 1) The method of claim 1, wherein the I/O operations between the host and the storage devices through the second data path are managed by a multi-path driver in the host. ### Claim 5 (depends on 1) The method of claim 1, wherein the virtual volumes are mapped one-to-one to the storage devices. ### Claim 6 (depends on 1) The method of claim 1, wherein the virtual volumes are image mode virtual disks provided by the virtualization controller. ### Claim 7 A computer program product comprising a computer readable storage medium having computer readable program code embodied therewith, the computer readable program code that when executed by a processor performs operations, the operations comprising: establishing a first data path between a host and a storage controller that interfaces with the host and a plurality of storage devices for storing data, wherein the host accesses the disks through the storage controller, wherein the host and the disks are in a communication zone; adding a virtualization controller to map the storage devices to a plurality of virtual volumes; establishing a second data path between the host and the storage devices through the virtual volumes, wherein the host recognizes the virtual volumes as an alternate data path to the first data path between the hosts and the storage devices; removing the first data path between the host and the storage controller in response to establishing the second data path, wherein the virtualization controller is configured without disrupting I/O operations between the host and the disks; and performing I/O operations between the host and the disks through the second data path and the virtualization controller. ### Claim 8 (depends on 7) The computer program product of claim 7, wherein the storage devices are coupled to the storage controller, and the storage controller is coupled to the host. ### Claim 9 (depends on 7) The computer program product of claim 7, wherein the operations further comprise disabling data caching in the virtualization controller. ### Claim 10 (depends on 7) The computer program product of claim 7, wherein the operations further comprise managing the I/O operations between the host and the storage devices through the second data path. ### Claim 11 (depends on 7) The computer program product of claim 7, wherein the operations further comprise recognizing alternate data paths between the host and the storage devices through the virtualization controller. ### Claim 12 (depends on 7) The computer program product of claim 7, wherein the virtual volumes correspond to SCSI unique identifiers of the storage devices. ### Claim 13 (depends on 7) The computer program product of claim 7, wherein the operations further comprise mapping the virtual volumes to the storage devices. ### Claim 14 (depends on 7) The computer program product of claim 7, wherein the virtual volumes are image mode virtual storage devices provided by the virtualization controller. ### Claim 15 A controller system configured to be coupled to a storage area network (SAN), the controller system comprising: a memory; a processor coupled to the memory and configured to: establish a first data path between a host and a storage controller that interfaces with the host and a plurality of storage devices for storing data, wherein the host accesses the disks through the storage controller, wherein the host and the disks are in a communication zone; add after establishing the first data path, a virtualization controller to map the storage devices to a plurality of virtual volumes and establishes a second data path between the host and the storage devices through the virtual volumes, wherein the host recognizes the virtual volumes as an alternate data path to the first data path between the hosts and the storage devices; removing the first data path between the host and the storage controller in response to establishing the second data path, wherein the virtualization controller is configured without disrupting I/O operations between the host and the disks; and performing I/O operations between the host and the storage devices through the second data path and the virtualization controller. ### Claim 16 (depends on 15) The controller system of claim 15, wherein data caching in the controller system is disabled during a configuration of the controller system. ### Claim 17 (depends on 15) The controller system of claim 15, wherein the I/O operations between the host and the storage devices through the second data path are managed by a multi-path driver in the host. ### Claim 18 (depends on 15) The controller system of claim 15, further comprising a host driver for recognizing alternate data paths between the host and the storage devices through the system. ### Claim 19 (depends on 15) The controller system of claim 15, wherein the virtual volumes correspond to SCSI unique identifiers of the storage devices. ### Claim 20 (depends on 15) The controller system of claim 15, wherein the virtual volumes are mapped one-to-one to the storage devices.