Microsoft Corporation
Data preservation using memory aperture flush order

Abstract:

Combined operational steps and device characteristics help preserve data against integrity threats. Data is divided into critical data and non-critical data, based on criteria such as customer requirements, workload criticality, or virtual machine criticality. Data may be generated in a compute node for storage in a storage node, for example. Critical data is stored in a battery-backed memory aperture at physical addresses where it will be flushed ahead of the non-critical data due to a flush order imposed by or on the battery-backed memory, e.g., a bottom-up NVDIMM flush order. Redundant copies of the data (especially non-critical data) may also be kept in case it does not get flushed in time. Battery-backed memory apertures are sized and located according to their battery's characteristics, and may be relocated or resized as conditions change. Flush defragging is performed to optimize use of the aperture, especially within the portion that holds critical data.