If you just want light-weight mirroring I recommend lsyncd. For example work if you want to work on code locally and have it mirrored on a remote host. It's more reliable because it just mirrors files rather than mounting file systems or block devices.

  Lsyncd uses a filesystem event interface (inotify or fsevents) to watch for changes to local files and directories. Lsyncd collates these events for several seconds and then spawns one or more processes to synchronize the changes to a remote filesystem. The default synchronization method is rsync. Thus, Lsyncd is a light-weight live mirror solution. Lsyncd is comparatively easy to install and does not require new filesystems or block devices. Lysncd does not hamper local filesystem performance.

https://lsyncd.github.io/lsyncd/