Emc IP Holding Company LLC

Dustin Hunt Zentz

Owen Martin

Adnan Sahin

Vladimir Desyatov

Kuolin Hua

Anoop Raghunathan

Mark D Moreau

Sean B Reilly

Embodiments of the present disclosure relate to establishing persistent cache memory as a write tier. An input/output (IO) workload of a storage array can be analyzed. One or more write data portions of the IO workload can be stored in a persistent memory region of one or more disks of the storage array.

Persistent memory adaptation

The over-provisioning (OP) of a physical storage device (PSD) may be increased, and the useful life of the PSD increased, by converting uncompressed data stored on the PSD to compressed data. It may be determined that increasing the useful life of the PSD, and the data reduction resulting from the compression, outweigh the benefit of faster I/O response times if the data remains uncompressed. A first portion of the PSD may be initially reserved for compression. A second portion of the PSD may store compressed data. It may be determined whether it is desirable to increase the OP of the PSD to thereby reduce the effective write rate on the PSD. If compression is determined to be desirable, the dynamic portion may be compressed, thereby reducing the amount of storage space consumed by the data, and freeing up storage space that can be used by the PSD for OP.

Dynamic overprovisioning of storage device

Techniques for performing data movements may include tracking sets of I/O statistics for a extents, wherein each of the sets of I/O statistics characterizes I/O operations directed to a corresponding one of the extents having data stored on a first storage tier of first non-volatile storage devices; determining, in accordance with the sets of I/O statistics, a list that includes one or more of the extents qualified for promotion from the first storage tier to a second storage tier, wherein the second storage tier includes second non-volatile storage devices have a higher performance ranking that the first non-volatile storage devices of the first storage tier; selecting, from the list, a first extent to be promoted from the first storage tier to the second storage tier; and performing first processing that promotes only cached data of the first extent from the first storage tier to the second storage tier.

Caching and data promotion techniques

Moving data among a plurality of non-volatile storage devices of a storage device includes accumulating credits at each of a plurality of periodic intervals for separate portions of the devices, wherein the credits correspond to a wear rating for each of the devices, reducing credits for each of the portions at each of the periodic intervals based on an amount of data written to each of the portions during each of the intervals, on the wear rating for each of the devices, and on a percent life used for the devices, and moving data from a first one of the portions having a relatively low amount of credits to a second one of the portions having a relatively high amount of credits. The devices may be solid state drives. The wear rating may be a drive writes per day rating provided by a manufacture of the solid state drive.

Dynamic re-balancing in heterogeneous storage systems

Techniques for processing I/O operations may include: randomly assigning extent identifiers of extents to RAID groups; receiving write activity information for the extents for a sampling period; for each of the RAID groups, performing stream detection processing in accordance with the first write activity information and determining stream groups, wherein each stream group of one of the RAID groups includes extents of the RAID group belonging to a same write stream in the RAID group, wherein stream groups across all RAID groups are uniquely identified using stream group identifiers; tagging a write operation directed to one of the extents with a first stream group identifier denoting a stream group including the one extent; and issuing the write operation to a solid state drive of one of the RAID groups. Stream detection may use K-Means clustering algorithm. An aggregate address range of logical devices is mapped to the extent identifiers.

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Northborough, MA, United States of America

Dustin Hunt Zentz