Reported at: https://discuss.elastic.co/t/combine-elasticsearch-5-1-1-and-repository-hdfs/69659

If you define as described in our docs the following elasticsearch.yml settings:

repositories:
  hdfs:
    uri: "hdfs://es-master:9000/" # optional - Hadoop file-system URI
    path: "some/path" # required - path with the file-system where data is stored/loaded

It fails at startup because we don't register the global setting repositories.hdfs.path in HdfsPlugin.

We should either support all global repositories.hdfs settings we documented or remove that from our docs so people must provide those settings only when registering the repository with:

PUT _snapshot/my_hdfs_repository
{
  "type": "hdfs",
  "settings": {
    "uri": "hdfs://namenode:8020/",
    "path": "elasticsearch/respositories/my_hdfs_repository",
    "conf.dfs.client.read.shortcircuit": "true"
  }
}