  Network transfer and disk read are the most time consuming operations in the
repair process for node failures in erasure-code-based distributed storage
systems. Recent developments on Reed-Solomon codes, the most widely used
erasure codes in practical storage systems, have shown that efficient repair
schemes specifically tailored to these codes can significantly reduce the
network bandwidth spent to recover single failures. However, the I/O cost, that
is, the number of disk reads performed in these repair schemes remains largely
unknown. We take the first step to address this gap in the literature by
investigating the I/O costs of some existing repair schemes for full-length
Reed-Solomon codes.
