I came across on this issue on ectd #2646, it is quite old post but I can't find anything on the docs.
Does etcd has its own storage engine, or it is using boltdb or some other backend?
Thanks
it appears so:
https://github.com/coreos/etcd/blob/master/Gopkg.lock
[[projects]]
name = "github.com/coreos/bbolt"
packages = ["."]
revision = "48ea1b39c25fc1bab3506fbc712ecbaa842c4d2d"
version = "v1.3.1-coreos.6"
https://github.com/coreos/etcd/search?utf8=%E2%9C%93&q=bbolt&type=