  In distributed storage, erasure codes -- like Reed-Solomon Codes -- are often
employed to provide reliability. In this setting, it is desirable to be able to
repair one or more failed nodes while minimizing the repair bandwidth. In this
work, motivated by Reed-Solomon codes, we study the problem of repairing
multiple failed nodes in a scalar MDS code. We extend the framework of
(Guruswami and Wootters, 2017) to give a framework for constructing repair
schemes for multiple failures in general scalar MDS codes, in the centralized
repair model. We then specialize our framework to Reed-Solomon codes, and
extend and improve upon recent results of (Dau et al., 2017).
