This section will guide you to the process of mounting host volume into DC/OS Data Science Engine and also providing User ID or Group ID to match necessary permissions.
Service Configurations
Assuming that there is a volume on the host /path/to/data where your data resides and ownership of this volume is 1000:1000 that means User ID is 1000 and Group ID is also 1000.
NOTE: You must decide the User/Group ID while initially installing the service, especially the User ID. You will not be able to change it for a running service.
To mount this volume into the service, configure it as follows:
{
  "storage": {
    "host_path": {
      "enabled": true,
      "container_path": "mydata",
      "path": "/path/to/data"
    }
  },
  "service": {
    "user_id": 1000,
    "group_id": 1000
  }
}
This will make /path/to/data available at /mnt/mesos/sandbox/mydata in the service.
Data Science Engine Documentation