# US 9,519,435 B2 · Synchronous extent migration protocol for paired storage > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,519,435 B2 - Document ID: US9519435B2 - Status: Granted - Kind: B2 - Application number: 15/175,426 - Filed: 2016-06-07 - Published: 2016-10-06 - Granted: 2016-12-13 - Earliest claimed: 2010-12-16 - Assignees: International Business Machines Corporation - Applicants: International Business Machines Corporation - Inventors: Paul A. Jennas, II; Larry Juarez; David Montgomery; Todd C. Sorenson - Web page: https://patentgrep.com/patent/US9519435B2 ## CPC - G06F 3/0619: {in relation to data integrity, e.g. data losses, bit errors} - G06F 3/0611: {in relation to response time} - G06F 3/0614: {Improving the reliability of storage systems} - G06F 3/0647: {Migration mechanisms} - G06F 3/0649: {Lifecycle management} - G06F 3/065: {Replication mechanisms} - G06F 3/067: {Distributed or networked storage systems, e.g. storage area networks [SAN], network attached storage [NAS]} - G06F 3/0683: {Plurality of storage devices} - G06F 3/0685: {Hybrid storage combining heterogeneous device types, e.g. hierarchical storage, hybrid arrays} - G06F 3/0689: {Disk arrays, e.g. RAID, JBOD} - G06F 11/2097: {maintaining the standby controller/processing unit updated (initialisation or re-synchronisation thereof G06F11/1658 and subgroups)} - H04L 67/1095: Replication or mirroring of data, e.g. scheduling or transport for data synchronisation between network nodes - 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 Extent migration is provided in a data storage environment configured for synchronous replication between a primary and secondary pair of storage entities, each having tiered storage devices. In one embodiment, by way of example only, a migration instruction is sent, by the primary storage entity, to the secondary storage entity, the migration instruction including a time delta approximately equal to a time of an intended migration at the primary storage entity such that the primary and secondary storage entities conduct the extent migration at approximately a same time. A relative priority is used against a secondary ordered heat map of the tiered storage devices of the secondary storage entity to perform the extent migration, regardless of whether the primary and secondary storage entities are identical. ## Claims ### Claim 1 In a data storage environment configured for synchronous replication between a primary and secondary pair of storage entities, each having tiered storage devices, a method for extent migration by a processor device, comprising: sending, by the primary storage entity, a migration instruction to the secondary storage entity, the migration instruction including a time delta approximately equal to a time of an intended migration at the primary storage entity such that the primary and secondary storage entities conduct the extent migration at approximately a same time; wherein a relative priority is used against a secondary ordered heat map of the tiered storage devices of the secondary storage entity to perform the extent migration, regardless of whether the primary and secondary storage entities are identical. ### Claim 2 (depends on 1) The method of claim 1, wherein the migration instruction further includes the relative priority based on a primary ordered heat map of the tiered storage devices of the primary storage entity. ### Claim 3 (depends on 1) The method of claim 1, further including, by at least a storage activity factor, identifying an extent as a candidate for the extent migration. ### Claim 4 (depends on 2) The method of claim 2, further including configuring the migration instruction with at least one of a message type field, an extent identifier field, a time delta field in which the time delta is incorporated, a destination tier number field, and a relative priority field. ### Claim 5 (depends on 4) The method of claim 4, further including, upon receipt of the migration instruction by the secondary storage entity: determining, using the relative priority, which of the tiered storage devices of the secondary storage entity to migrate the extent, and acknowledging which of the tiered storage devices of the secondary storage entity to the primary storage entity. ### Claim 6 (depends on 5) The method of claim 5, further including determining, by the primary storage entity, based on the acknowledgment of the secondary storage entity, whether to perform the extent migration to which of the tiered storage devices. ### Claim 7 (depends on 6) The method of claim 6, wherein the determining whether to perform the extent migration includes considering at least one of a read/write ratio, a ratio of sequential to non-sequential access, and a quality of service requirement. ### Claim 8 A system for, in a data storage environment configured for synchronous replication between a primary and secondary pair of storage entities, each having tiered storage devices, a system for extent migration, comprising: at least one storage management module, operable in the data storage environment, wherein the at least one storage management module is adapted for: sending, by the primary storage entity, a migration instruction to the secondary storage entity, the migration instruction including a time delta approximately equal to a time of an intended migration at the primary storage entity such that the primary and secondary storage entities conduct the extent migration at approximately a same time; wherein a relative priority is used against a secondary ordered heat map of the tiered storage devices of the secondary storage entity to perform the extent migration, regardless of whether the primary and secondary storage entities are identical. ### Claim 9 (depends on 8) The system of claim 8, wherein the migration instruction further includes the relative priority based on a primary ordered heat map of the tiered storage devices of the primary storage entity. ### Claim 10 (depends on 8) The system of claim 8, wherein the at least one storage management module is further adapted for, by at least a storage activity factor, identifying an extent as a candidate for the extent migration. ### Claim 11 (depends on 9) The system of claim 9, wherein the at least one storage management module is further adapted for configuring the migration instruction with at least one of a message type field, an extent identifier field, a time delta field, in which the time delta is incorporated, a destination tier number field, and a relative priority field. ### Claim 12 (depends on 11) The system of claim 11, wherein the at least one storage management module is further adapted for, upon receipt of the migration instruction by the secondary storage entity: determining, using the relative priority, which of the tiered storage devices of the secondary storage entity to migrate the extent, and acknowledging the which of the tiered storage devices of the secondary storage entity to the primary storage entity. ### Claim 13 (depends on 12) The system of claim 12, wherein the at least one storage management module is further adapted for determining, by the primary storage entity, based on the acknowledgment of the secondary storage entity, whether to perform the extent migration to the which of the tiered storage devices. ### Claim 14 (depends on 13) The system of claim 13, wherein at least one storage management module is further adapted for, pursuant to the determining whether to perform the extent migration, considering at least one of a read/write ratio, a ratio of sequential to non-sequential access, and a quality of service requirement. ### Claim 15 (depends on 8) The system of claim 8, wherein: the at least one storage management module is operable as a storage management processor (SMP) device, and the primary and secondary storage entities include at least one of a tape tier, an enterprise drive tier, a solid state drive (SSD) tier, and a cache tier for conducting the extent migration therebetween. ### Claim 16 A computer program product for, in a data storage environment configured for synchronous replication between a primary and secondary pair of storage entities, each having tiered storage devices, extent migration by a processor device, the computer program product comprising a non-transitory computer-readable storage medium having computer-readable program code portions stored therein, the computer-readable program code portions comprising: an executable portion for sending, by the primary storage entity, a migration instruction to the secondary storage entity, the migration instruction including a time delta approximately equal to a time of an intended migration at the primary storage entity such that the primary and secondary storage entities conduct the extent migration at approximately a same time; wherein a relative priority is used against a secondary ordered heat map of the tiered storage devices of the secondary storage entity to perform the extent migration, regardless of whether the primary and secondary storage entities are identical. ### Claim 17 (depends on 16) The computer program product of claim 16, wherein the migration instruction further includes the relative priority based on a primary ordered heat map of the tiered storage devices of the primary storage entity. ### Claim 18 (depends on 16) The computer program product of claim 16, further including an executable portion for, by at least a storage activity factor, identifying an extent as a candidate for the extent migration. ### Claim 19 (depends on 17) The computer program product of claim 17, further including an executable portion for configuring the migration instruction with at least one of a message type field, an extent identifier field, a time delta field, in which the time delta is incorporated, a destination tier number field, and a relative priority field. ### Claim 20 (depends on 19) The computer program product of claim 19, further including an executable portion for, upon receipt of the migration instruction by the secondary storage entity: determining, using the relative priority, which of the tiered storage devices of the secondary storage entity to migrate the extent, and acknowledging the which of the tiered storage devices of the secondary storage entity to the primary storage entity. ### Claim 21 (depends on 20) The computer program product of claim 20, further including an executable portion for determining, by the primary storage entity, based on the acknowledgment of the secondary storage entity, whether to perform the extent migration to the which of the tiered storage devices; wherein the determining whether to perform the extent migration includes considering at least one of a read/write ratio, a ratio of sequential to non-sequential access, and a quality of service requirement.