Binary Codes with Locality for Multiple Erasures Having Short Block Length

The focus of this paper is on linear, binary codes with locality having locality parameter $r$, that are capable of recovering from $t\geq 2$ erasures and that moreover, have short block length. Both sequential and parallel (through orthogonal parity checks) recovery is considered here. In the case of parallel repair, minimum-block-length constructions for general $t$ are discussed. In the case of sequential repair, the results include (a) extending and characterizing minimum-block-length constructions for $t=2$, (b) providing improved bounds on block length for $t=3$ as well as a general construction for $t=3$ having short block length, (c) providing short-block-length constructions for general $r,t$ and (d) providing high-rate constructions for $r=2$ and $t$ in the range $4 \leq t \leq7$. Most of the constructions provided are of binary codes.