System and method for fault-tolerant synchronization of replica updates for fixed persistent consistency point image consumption

摘要

A system and method for fault-tolerant synchronization of replica updates for fixed persistent consistency point image consumption. PCPIs are consumed at a fixed level and each coalesced PCPI presents a valid version of the source file system from some point in time. The qtrees concurrently move through a coalescing cycle wherein some qtrees are updated, some may update partially and some may not update at all. Partially updated qtrees are rolled-back to the previous state, after which all qtrees are transitioned to a stable state.