Techniques are described for checkpointing multiple key ranges in parallel and concurrently during file storage replications between file systems in different cloud infrastructure regions. In certain embodiments, multiple range threads processing multiple key ranges, one thread per key range, create checkpoints for their respective key ranges in parallel and concurrently after processing a per-determined number of B-tree keys. In certain embodiments, upon encountering a failure event, either a system crash or a thread failure, each thread restarts its B-tree key processing from a B-tree key after the most recent checkpoint.