Pelican: A Building Block for Exascale Cold Data Storage

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Author(s)/Presenter(s):

Austin Donnelly

Library Content Type

Presentation

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Focus Areas

Abstract

Pelican is a rack-scale design for cheap storage of data which is rarely accessed: cold data. It uses spun-down hard drives to maximise density and reduce costs. A Pelican rack supplies only enough resources (power, cooling, bandwidth) to support the cold data workloads we target, significantly reducing Pelican's total cost of ownership compared to traditional disk-based systems provisioned for peak performance.

The Pelican storage stack manages the limited resources, and their constraints. We describe the data layout and IO scheduling algorithms which ensures these constraints are not violated, while making best use of the available resources. We evaluate Pelican both in simulation and with a full rack, and show that Pelican performs well: delivering both high throughput and acceptable latency.