Re: Good short explanation of RAID vs. Erasure Coding
Object storage is considered secondary storage and therefore performance has not been a major criteria. One object storage software, Scality, claims that tests run on their RING storage clusters equal the performance of primary data storage systems. The object storage software vendors who offer erasure coding in addition to replication include Caringo, Cloudian and Scality. Ceph's commercial sponsor, InkTank, was recently purchased by Red Hat. Sage Weil, who developed Ceph as part of his PhD work, is a genius kind of guy, but Ceph has not seen wide spread deployment in commercial environments yet. Ditto for Swift. Other object storage vendors, like Amplidata and Cleversafe, base their object storage solely on the use of erasure codes. While some erasure codes are proprietary, many are based on or derived from Reed-Solomon, which has been around since the days of X.25 packet switching networks. I recall back in the day that a lot of 1/4-inch cartridge tape drives and 4mm DAT drives used Reed-Solomon ECC to reliably write data to tape.