Recovery point objective via dynamic usage of bind segments in a global mirror environment

Abstract

Embodiments for an approach to resource optimization during consistency group formation associated with a global mirror environment is provided. The approach detects when a primary volume associated with the consistency group has completed transmitting its out-of-sync (OOS) data towards its associated secondary volume. A command is sent to create a next consistency group sidefile so further writes can be sent to the sidefile rather than queueing at the primary volume. The approach repeats this process for each primary volume associated with the global mirror environment until all primary volumes are complete. Commands are sent to disable writes to the associated sidefiles and to merge the data stored in the sidefiles into normal cache as the next consistency group becomes the current consistency group.

1 . A method for consistency group formation, the method comprising:
 determining, by one or more primary storage devices, if a first primary volume of a plurality of primary volumes associated with a current consistency group has completed sending out-of-sync (OOS) data towards one or more secondary volumes associated with the plurality of primary volumes, respectively;   responsive to the first primary volume completing sending OOS data, sending, by the one or more primary storage devices, an “EnableNextCGSidefiles” command, not associated with the current consistency group, to generate a storage location, associated with a next consistency group, in cache associated with a secondary volume, wherein the secondary volume executes the “EnableNextCGSidefiles” command and wherein the storage location is a “NextCGSidefile” and further writes are directed, by the one or more primary storage devices, to the “NextCGSidefile i ”   sending, by the one or more primary storage devices, change recording (CR) data for the next consistency group toward the secondary volume for storage in the “NextCGSidefile;”   determining, by the one or more primary storage devices, if the plurality of primary volumes associated with the current consistency group have completed sending out-of-sync (OOS) data towards a plurality of secondary volumes associated with the plurality of primary volumes, respectively;   responsive to the plurality of primary volumes completing sending OOS data, stop sending, by the one or more primary storage devices, CR data toward the plurality of secondary volumes, respectively;   sending, by the one or more primary storage devices, a “DisableNextCGSidefiles” command toward the plurality of secondary volumes, wherein the secondary volumes execute the “DisableNextCGSidefiles” command, respectively, and wherein the “DisableNextCGSidefiles” command directs further writes towards the cache associated with a secondary volume;   sending, by the one or more primary storage devices, a “HardenNextCGSidefiles” command toward the plurality of secondary volumes, wherein the secondary volumes execute the “HardenNextCGSidefiles” command, respectively, and wherein the “HardenNextCGSidefiles” command directs merging data associated with the “NextCGSidefile” with the current consistency group and the plurality of secondary volumes are associated with a global mirror environment; and   sending, by the one or more primary storage devices, a “FlushNextCGSidefiles” command towards the plurality of secondary volumes, wherein the secondary volumes execute the “FlushNextCGSidefiles” command, respectively.