Use of compression domains that are more granular than storage allocation units
AssigneeDell Products L.P.
InventorsRong Yu, Michael Scharland, Jeremy O'Hare
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Abstract
Within a storage array, allocation of physical storage capacity within a storage array may be managed in standard size allocation units of uncompressed data, e.g. 128kb tracks, while smaller sub-allocation unit compression domains, e.g. 32kb quarter tracks, are used for compressed data. The data within a sub-allocation unit may be compressed to a size that is less than the capacity of the sub-allocation unit. Data associated with sub-allocation units that are not required to service a read or write may not need to be compressed or decompressed in order to service the read or write. Consequently, resource usage may be more efficient.
Claims20
An apparatus comprising:
- a storage array comprising:
- a plurality of tangible data storage devices;
- and
- a computing node comprising a processor and a cache, wherein the computing node presents a production volume to a host application and, in response to first and second IO requests from the host application, the processor determines that first data corresponding to the first IO request is to be stored in a compressed state and that second data corresponding to the second IO request is to be stored in an uncompressed state, and wherein the processor prompts storage of fixed size allocation units of the first data on the tangible storage devices to service the first IO request, and wherein the processor prompts compression of sub-allocation units of the second data to service the second IO request, each sub-allocation unit comprising a compression domain having a smaller size than ones of the fixed size allocation units of the first data, resulting compressed sub-allocation units of data being stored on the tangible storage devices.
A method comprising:
- with a storage array comprising a plurality of tangible data storage devices and a computing node comprising a processor and a cache, the computing node presenting a production volume to a host application;
- in response to first and second IO requests from the host application, the processor determining that first data corresponding to the first IO request is to be stored in a compressed state and that second data corresponding to the second IO request is to be stored in an uncompressed state;
- the processor prompting storage of fixed size allocation units of the first data on the tangible storage devices to service the first IO request;
- and
- the processor prompting compression of sub-allocation units of the second data to service the second IO request, each sub-allocation unit comprising a compression domain having a smaller size than ones of the fixed size allocation units of the first data, resulting compressed sub-allocation units of data being stored on the tangible storage devices.
Dependencies are inferred from the claim text.