It is imperative for any file system to be highly scalable, performant, and fault tolerant. Otherwise…why would you even bother to store data there? But realistically, achieving fault tolerance is done through data redundancy. On the flipside, the cost of redundancy is increased storage overhead. There are two possible encoding schemes for fault tolerance: triple mirroring (RF3) and erasure coding. To ensure the Scale Data Distributed Filesystem (SDFS, codenamed “Atlas”) is fault tolerant while increasing capacity and maintaining higher performance, Rubrik uses a schema called erasure coding.