Lower Bound on the Optimal Access Bandwidth of ($K+2,K,2$)-MDS Array Code with Degraded Read Friendly

TL;DR

This paper establishes a lower bound on the access bandwidth for a specific class of MDS array codes designed to facilitate low-latency degraded reads in erasure-coded storage systems.

Contribution

It derives the first theoretical lower bound on access bandwidth for (K+2,K,2)-MDS array codes that are degraded-read friendly with minimal sub-packetization.

Findings

Lower bound on access bandwidth is established for the specified code class.

The bound applies to codes with 2 redundant nodes and sub-packetization level of 2.

Results inform the design of efficient erasure-coded storage systems.

Abstract

Accessing the data in the failed disk (degraded read) with low latency is crucial for an erasure-coded storage system. In this work, the maximum distance separable (MDS) array code with the property of degraded-read friendly (DRF) is discussed. For the DRF MDS array code with 2 redundant nodes and the sub-packetization level of 2, the lower bound of its access bandwidth is derived.