US 9,804,973 B1 · Using frequency domain to prioritize storage of metadata in a cache

Abstract

A system and method for efficiently caching metadata in a storage system. Addresses from a plurality of I/O accesses to the storage system are captured and then a frequency domain representation of the addresses is generated. The frequency domain representation is used to measure the randomness of the various applications which are accessing the storage system. Scores are generated based on the measure of randomness, and scores are assigned to the various regions of the logical address space. Scores are then assigned to the metadata pages which are stored in the cache based on the region of the logical address space to which the metadata pages correspond. The scores are used when determining which metadata pages to evict from the cache. The cache will attempt to evict those metadata pages which correspond to regions of the logical address space that are servicing random I/O accesses.

Claims20

Dependent claims

A method comprising:

measuring an amount of randomness within a plurality of addresses that are referenced in a plurality of accesses to one or more storage devices including adding together frequency component values above a first cutoff frequency in a first frequency distribution of a first frequency domain representation of the plurality of addresses of the plurality of accesses;
and
caching, in dependence upon the amount of randomness for each of the plurality of addresses, metadata associated with one or more of the plurality of addresses.

Dependencies are inferred from the claim text.

Using frequency domain to prioritize storage of metadata in a cache

Life of this patent

Using frequency domain to prioritize storage of metadata in a cache

Life of this patent

Abstract

Claims20