Linear Exact-Repair Construction of Hybrid MSR Codes in Distributed Storage Systems

An [n, k, d]-hybrid minimum storage regenerating (HMSR) codes is one class of minimum storage regenerating (MSR) codes where each storage node stores two symbols in a distributed storage system (DSS). Due to the ability of reducing repair bandwidth and minimizing disk I/O cost, HMSR codes are proper to be used in practice. In this letter, we prove that there exists no linear exact-repair HMSR codes when k ≥ 5. A construction of [6,3,4]-HMSR codes is devised in F₂. Focused on [4,2,3]-HMSR codes, a repair-by-transfer construction and the corresponding regenerating algorithm are proposed.