# US 9,436,406 B2 · Migration decision window selection based on hotspot characteristics > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,436,406 B2 - Document ID: US9436406B2 - Status: Granted - Kind: B2 - Application number: 14/324,276 - Filed: 2014-07-07 - Published: 2016-01-07 - Granted: 2016-09-06 - Earliest claimed: 2014-07-07 - Assignees: International Business Machines Corporation - Applicants: International Business Machines Corporation - Inventors: Lawrence Y. Chiu; Sangeetha Seshadri; Yang Zhou - Web page: https://patentgrep.com/patent/US9436406B2 ## CPC - G06F 3/0649: {Lifecycle management} - G06F 3/0608: {Saving storage space on storage systems} - G06F 3/061: {Improving I/O performance} - G06F 3/067: {Distributed or networked storage systems, e.g. storage area networks [SAN], network attached storage [NAS]} - G06F 3/0685: {Hybrid storage combining heterogeneous device types, e.g. hierarchical storage, hybrid arrays} - G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N) ## Abstract Methods and arrangements for selecting a migration decision window for hotspots in a multi-tier enterprise storage system. Aspects include collecting usage statistics for data stored in the multi-tier enterprise storage system, identifying hotspots from data stored in the multi-tier enterprise storage system based on the usage statistics, and determining one or more characteristics of the identified hotspots. Aspects further include calculating an average lifespan of the identified hotspots based on the one or more characteristics of the identified hotspots and selecting the migration decision window based on the average lifespan of the identified hotspots and the one or more characteristics of the identified hotspots. ## Claims ### Claim 1 A method for migrating storage hotspots in a multi-tier enterprise storage system, comprising: collecting usage statistics for data stored in the multi-tier enterprise storage system in real-time; identifying a plurality of hotspots from data stored in the multi-tier enterprise storage system based on the usage statistics collected; determining one or more characteristics of the plurality of hotspots identified; calculating an average lifespan of the plurality of hotspots identified based on the one or more characteristics of the plurality of hotspots identified; and migrating the plurality of hotspots identified in real-time to one or more high performance storage devices based on the average lifespan of the plurality of hotspots identified and the one or more characteristics of the plurality of hotspots identified. ### Claim 2 (depends on 1) The method of claim 1, wherein the one or more characteristics of the plurality of hotspots identified comprise at least one of a lifespan of the plurality of hotspots identified and a size of the plurality of hotspots identified. ### Claim 3 (depends on 1) The method of claim 1, wherein the migration decision window is selected to be half of the average lifespan of the plurality of hotspots identified. ### Claim 4 (depends on 1) The method of claim 1, wherein the migration decision window is selected to be a predetermined value if the average lifespan of the plurality of hotspots identified is below a minimum threshold value. ### Claim 5 (depends on 4) The method of claim 4, wherein the minimum threshold value is based on a migration bandwidth of the multi-tier enterprise storage system. ### Claim 6 (depends on 1) The method of claim 1, wherein the usage statistics comprise at least one of: an average input/output (I/O) size; an I/O count, a sequential read count; a random read count; a sequential write count; a random write count; and a latency. ### Claim 7 A computer program product for migrating storage hotspots in a multi-tier enterprise storage system, comprising: a non-transitory computer readable storage medium storing computer executable instructions, when executed by a processor of the multi-tier enterprise storage system, the computer executable instructions cause the processor to perform: collecting usage statistics for data stored in the multi-tier enterprise storage system in real-time; identifying a plurality of hotspots from data stored in the multi-tier enterprise storage system based on the usage statistics collected; determining one or more characteristics of the plurality of hotspots identified; calculating an average lifespan of the plurality of hotspots identified based on the one or more characteristics of the plurality of hotspots identified; and migrating the plurality of hotspots identified in real-time to one or more high performance storage devices based on the average lifespan of the plurality of hotspots identified and the one or more characteristics of the plurality of hotspots identified. ### Claim 8 (depends on 7) The computer program product of claim 7, wherein the one or more characteristics of the plurality of hotspots identified comprise at least one of a lifespan of the plurality of hotspots identified and a size of the plurality of hotspots identified. ### Claim 9 (depends on 7) The computer program product of claim 7, wherein the migration decision window is selected to be half of the average lifespan of the plurality of hotspots identified. ### Claim 10 (depends on 7) The computer program product of claim 7, wherein the migration decision window is selected to be a predetermined value if the average lifespan of the plurality of hotspots identified is below a minimum threshold value. ### Claim 11 (depends on 10) The computer program product of claim 10, wherein the minimum threshold value is based on a migration bandwidth of the multi-tier enterprise storage system. ### Claim 12 (depends on 7) The computer program product of claim 7, wherein the usage statistics comprise at least one of: an average input/output (I/O) size; an I/O count, a sequential read count; a random read count; a sequential write count; a random write count; and a latency. ### Claim 13 A multi-tier enterprise storage system comprising: a plurality of storage devices; a computer system in communication with the plurality of storage devices, having a processor and a non-transitory computer readable storage medium storing computer executable instructions, when executed by the processor of the computer system, the computer executable instructions cause the processor to perform: collecting usage statistics for data stored in the multi-tier enterprise storage system in real-time; identifying a plurality of hotspots from data stored in the multi-tier enterprise storage system based on the usage statistics collected; determining one or more characteristics of the plurality of hotspots identified; calculating an average lifespan of the plurality of hotspots identified based on the one or more characteristics of the plurality of hotspots identified; and migrating the plurality of hotspots identified in real-time to one or more high performance storage devices based on the average lifespan of the plurality of hotspots identified and the one or more characteristics of the plurality of hotspots identified. ### Claim 14 (depends on 13) The multi-tier enterprise storage system of claim 13, wherein the computer system is configured to: manage data storage among the plurality of storage devices; and migrate data among the plurality of storage devices. ### Claim 15 (depends on 13) The multi-tier enterprise storage system of claim 13, wherein the plurality of storage devices comprises: one or more high performance storage devices; and one or more low performance storage devices. ### Claim 16 (depends on 13) The multi-tier enterprise storage system of claim 13, wherein the one or more characteristics of the plurality of hotspots identified comprise at least one of a lifespan of the plurality of hotspots identified and a size of the plurality of hotspots identified. ### Claim 17 (depends on 13) The multi-tier enterprise storage system of claim 13, wherein the migration decision window is selected to be half of the average lifespan of the plurality of hotspots identified. ### Claim 18 (depends on 13) The multi-tier enterprise storage system of claim 13, wherein the migration decision window is selected to be a predetermined value if the average lifespan of the plurality of hotspots identified is below a minimum threshold value. ### Claim 19 (depends on 18) The multi-tier enterprise storage system of claim 18, wherein the minimum threshold value is based on a migration bandwidth of the computer system. ### Claim 20 (depends on 13) The multi-tier enterprise storage system of claim 13, wherein the usage statistics comprise at least one of: an average input/output (I/O) size; an I/O count, a sequential read count; a random read count; a sequential write count; a random write count; and a latency.