> For the complete documentation index, see [llms.txt](https://docs.roadrunner.dev/docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.roadrunner.dev/docs/key-value/boltdb.md).

# BoltDB

This type of driver is already supported by the RoadRunner and does not require any additional installations.

## Configuration

The complete boltdb driver configuration:

{% code title=".rr.yaml" %}

```yaml
version: "3"

kv:
  # User defined name of the storage.
  boltdb:
    # Required section.
    # Should be "boltdb" for the boltdb driver.
    driver: boltdb

    config:
      # Optional section.
      # Default: "rr.db"
      file: "./rr.db"

      # Optional section.
      # Default: 0777
      permissions: 0777

      # Optional section.
      # Default: 60
      interval: 60
```

{% endcode %}

## Options

Below is a more detailed description of the various boltdb options.:

### File

`file`: Database file path name. In the case that such a file does not exist, RoadRunner will create this file on its own at startup. Note that this must be an existing directory, otherwise a "The system cannot find the path specified" error will occur, indicating that the full database pathname is invalid. Might be a full path with file: `/foo/bar/rr1.db`. Default: `rr.db`.

Use a separate database file for each KV storage. Each storage opens the file with an exclusive lock. Sharing a file between storage instances causes startup to fail.

The driver uses the fixed internal bucket `default`. It does not support a `bucket` configuration option.

### Permissions

`permissions`: The file permissions in UNIX format of the database file, set at the time of its creation. If the file already exists, the permissions will not be changed.

### Interval

`interval`: The time in seconds between expiration checks. Expired entries can remain readable until the next check.

## Persistence

Values remain in the database after a RoadRunner restart. Expiration timestamps are kept only in memory and are lost at restart. Reapply expiration timestamps from application data after startup if needed. Use [Redis](/docs/key-value/redis.md) when expiration must survive a RoadRunner restart.

Upgrading from v5 does not require a database format conversion. Stop RoadRunner before backing up the database file.

## Write Errors

`kv.Set` and `kv.Delete` return database commit errors through RPC. Handle these errors before treating a write or deletion as successful.