Nothing wrong with mounting volumes, but certainly not for production DB's, at least not at this point. I don't have much insight to share on this, besides my intuition based on several years working on HA systems. The clusterhq folks are working on this problem though, and I am following keenly.
Docker volumes are just bind-mounted directories. Of all the things you should worry about when running HA systems, bind-mounts is definitely not one of them. They are essentially overhead-free and completely stable. This is completely orthogonal to Docker - after setting up the bind-mounts it gets completely out of the way of the critical path.
We have definitely used them at large scale in production for several years with no issues.
Thanks shykes for chiming in on this. We use docker heavily for our applications in production (and all other envs), and would absolutely like to extend that to our Postgres DBs. Are there any examples you can point us to with a pattern for Postgres HA clusters with docker? Thanks.
