RMR and BRMR Documentation

Contents

Warning

RMR and BRMR are under active development and are not ready for production use. The codebase contains known bugs, incomplete features, and areas that require improvement, correction, or refactoring — expect instability and potential data loss. APIs and interfaces may change without notice.

RMR (Reliable Multicast over RTRS) is a kernel module that provides active-active block-level replication over RDMA. It guarantees delivery of IO to a group of storage nodes and handles resynchronization of data directly between storage nodes without involving the compute client.

BRMR (Block device over RMR) sits on top of RMR and exposes a standard Linux block device (/dev/brmrX) backed by an RMR pool. Together, RMR and BRMR provide a single-hop replication and resynchronization solution for RDMA-connected storage clusters.