# Containers

When running the docker image of NATS Streaming Server, you will want to specify a mounted volume so that the data can be recovered. Your `-dir` parameter then points to a directory inside that mounted volume. However, after a restart you may get a failure with a message similar to this:

```
[FTL] STREAM: Failed to start: streaming state was recovered but cluster log path "mycluster/a" is empty
```

This is because the server recovered the streaming state (as pointed by `-dir` and located in the mounted volume), but did not recover the RAFT specific state that is by default stored in a directory named after your cluster id, relative to the current directory starting the executable. In the context of a container, this data will be lost after the container is stopped.

In order to avoid this issue, you need to specify the `-cluster_log_path` and ensure that it points to the mounted volume so that the RAFT state can be recovered along with the Streaming state.


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://docs.natsclub.cn/cn/yi-chan/stan/intro/clustering/containers.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.
