Implementing High-Availability Observability via Grafana and Prometheus on Synology NAS using Docker

The deployment of a centralized observability stack on a Synology Network Attached Storage (NAS) device represents a pinnacle of home laboratory and small-scale enterprise infrastructure management. At its core, Grafana serves as the visualization and analytics engine, an open-source powerhouse designed to query, visualize, alert on, and decode complex metrics regardless of their underlying storage architecture. Whether the data resides in time-series databases, SQL instances, or cloud-native repositories, Grafana provides the interface necessary to transform raw numbers into actionable intelligence. Through the use of heatmaps, histograms, graphs, and geomaps, users can foster a data-driven culture within their digital ecosystem.

For the Synology administrator, the objective extends beyond mere visualization; it involves the orchestration of a containerized stack that includes Prometheus for time-series data collection, cAdvisor for container monitoring, Node Exporter for host metrics, and SNMP Exporters for network hardware telemetry. This architecture allows for the real-time monitoring of CPU utilization, memory consumption, network throughput, and even Uninterrupt/UPS statistics. By leveraging Docker—specifically the Container Manager package on modern Synology DiskStation Manager (DSM) versions—administrators can deploy a persistent, scalable, and highly visible monitoring layer that ensures the health and performance of their storage infrastructure are never in doubt.

Infrastructure Prerequisites and Environment Preparation

Before initiating the deployment of the Grafana stack, the underlying host environment must be properly configured to support containerized workloads and network-level data collection. The foundation of this setup is the presence of a compatible Synology NAS capable of running Docker.

The first critical requirement is the installation of the container orchestration engine. On Synology systems running DSM 7.2 or later, this package is known as Container Manager. For users operating on older versions of DSM (specifically any version prior to 7.2), the package is still listed under the name Docker within the Synology Package Center. The presence of this package is the fundamental prerequisite for all subsequent steps involving image pulling and volume mounting.

Beyond the software layer, the physical or virtual network configuration must be audited. A significant hurdle in many deployments is the Synology DSM Firewall. If the firewall is enabled, it will inherently block the traffic required by exporters (such as Prometheus or Node Exporter) to scrape metrics from the NAS. To ensure uninterrupted data flow, the following administrative actions are mandatory:

Navigate to the Control Panel within the DSM interface.
Access the Security section and select the Firewall configuration.
If the "Enable firewall" checkbox is active, click the "Edit Rules" button under the Firewall Profile.
Create a new rule under Firewall Rules by clicking the "Create" button.
and 5. Configure the rule to set Ports to "All" to prevent fragmentation of data streams.
Under the Source IP setting, select "Specific IP" and choose the "Subnet" option.
Input the subnet 172.22.0.0 with a subnet mask of 255.255.0.0.
Set the Action to "Allow" and ensure the "Enabled" checkbox is ticked.
Crucially, use the drag-and-drop interface to move this new rule to the very top of the firewall rule list to ensure it is processed before any restrictive rules.

Furthermore, for monitoring network hardware and the NAS itself via SNMP (Simple Network Management Protocol), the SNMP service must be explicitly enabled. This involves navigating to Control Panel, then Terminal and SNMP, and checking the "Enable SNMP service" box. For advanced security and monitoring depth, the SNMPv3 service should be activated, utilizing a specific username (such as exporter), the MD5 protocol, and a secure, predefined password.

Filesystem Architecture and Data Persistence

A common failure point in Docker deployments is the loss of configuration and historical data upon container updates or restarts. To achieve true persistence, a structured directory hierarchy must be established within the Synology File Station. This ensures that even if the container is destroyed and recreated, the underlying SQLite databases, InfluxDB metrics, and Grafana dashboards remain intact.

The deployment requires the creation of a dedicated docker folder within the primary volume of the NAS. Within this docker directory, a specific folder structure must be strictly adhered to, using lowercase letters to avoid pathing errors in Linux-based environments:

docker/grafana: This directory will serve as the mounting point for Grafana's internal configuration and data.
docker/influxdb: This directory will host the persistent storage for the InfluxDB time-series database.

When configuring the container, these folders must be mapped to the internal container paths. For the Grafana container, the local folder /docker/grafana should be mounted to the internal path /var/lib/grafana. For the InfluxDB component, the local folder /docker/influxdb must be mapped to /var/lib/influxdb. This mapping strategy ensures that all dashboard configurations, plugins, and historical metrics are stored on the NAS's permanent storage rather than the container's ephemeral writable layer.

Container Deployment and Stack Orchestration

The deployment can be achieved through various methods, including the Docker CLI, Docker Compose, or the Synology Container Manager GUI. A highly efficient method involves using a pre-integrated image stack, such as alhazmy13/telegraf-influxdb-grafana, which bundles the necessary components for a cohesive monitoring ecosystem.

To deploy this integrated stack, the administrator should follow these technical steps:

Open the Docker (or Container Manager) client from the Synology interface.
Navigate to the "Image" tab and select "Add" followed by "Add from url".
Input the Hub page URL: https://hub.docker.com/r/alhazmy13/telegraf-influxdb-grafana.
Monitor the download progress until the image is fully cached in the local registry.
Select the alhazmy13/telegraf-influxdb-grafana image and click "Launch".

During the container configuration phase, several advanced settings must be meticulously applied to ensure stability and connectivity:

Auto-Restart: Under the "Advanced Settings" menu, the "Enable auto-restart" option must be checked. This ensures that if the NAS reboots or the container crashes due to resource exhaustion, the monitoring stack recovers automatically without manual intervention.
Volume Mapping: As detailed in the filesystem section, the grafana and inflimgdb folders must be mapped to their respective /var/lib/ paths.
Network Configuration: The container should remain in "Bridge" mode to allow for controlled port mapping and isolation from the host network.
Port Mapping: To prevent conflicts with existing services on the NAS, specific local ports must be assigned. The Grafana service should be mapped from local port 3003 to the container's port 3003. Additionally, the Syslog or telemetry port should be mapped from local port 5144 to container port 514.
Environment Variables: To ensure time-accurate data logging, a new variable named TZ should be added to the "Environment" tab, containing your specific local time zone (e.g., America/New_York). If left blank, the system will default to UTC, which can lead to confusion when correlating logs with local events.

Regarding the choice of Grafana images, it is important to note a significant change in the official Docker Hub repository structure. As of Grafana release 12.4.0, the grafana/grafana-oss repository is no longer being updated. Users should instead utilize the grafana/grafana repository. While both provide the Open Source (OSS) functionality, the grafana/grafana image is the current standard. Furthermore, the grafana/grafana-enterprise image is recommended for those seeking the full feature set, as it includes all OSS features and provides the option to upgrade to Enterprise plugins.

Dashboard Configuration and Data Visualization

Once the container is running and accessible via http://YOUR_LOCAL_ARG_IP:3003, the next phase is the injection of intelligence through dashboard configuration. A raw Grafana installation provides the engine but lacks the specific "logic" for Synology monitoring.

To transform the empty interface into a comprehensive monitoring suite, administrators can utilize pre-configured JSON dashboard definitions. A highly regarded resource for this is the synology_dashboard.json file, which can be imported directly into the Grafana interface.

The process for dashboard implementation is as follows:

Access the Grafana web interface via your browser.
Locate the "Dashboards" section in the left-hand navigation menu.
Click on the "Import" button.
Upload or paste the contents of the synology_dashboard.json file.
Configure the data source connection to point to your Prometheus or InfluxDB instance.

When connecting data sources, particularly Prometheus, it is vital to verify the network addressability of the exporters. In certain complex Docker network topologies, a common error occurs where the Grafana dashboard attempts to reach Prometheus using a container name that is not resolvable. If the cAdvisor or Prometheus container fails to report data (indicated by an "exited" code or empty graphs), the administrator should attempt to replace the internal service URL (e.g., http://prometheus-server:9090/) with the direct IP address of the NAS (e.g., http://192.168.1.100:9090/).

A robust Synology dashboard stack can encompass a wide array of exporters to provide a holistic view:

Grafana: The primary visualization engine.
Prometheus: The time-series database and scraping engine.
cAdvisor: For monitoring container-level resource usage.
Node Exporter: For monitoring the host operating system metrics.
SNMP Exporter: For monitoring network switches and UPS hardware.
Speedtest Exporter: For tracking internet throughput.
UPS Stats: For monitoring power redundancy and battery health.

Advanced Maintenance and Troubleshooting

Maintaining a production-grade monitoring stack requires periodic attention to software updates and configuration changes. One of the most frequent queries in the community involves updating Grafana within a Docker environment without losing existing dashboards, users, or historical data.

Because the deployment architecture relies on volume mounting (as established in the filesystem section), updating the Grafana container is a relatively safe operation. Since the configuration resides in /docker/grafana on the host, pulling a new image and recreating the container will not destroy the underlying data. However, extreme caution must be exercised when modifying environment variables. For example, if you are migrating from a configuration that uses a list of plugins to a new version, ensure that the GF_INSTALL_PLuggins variable is correctly formatted.

Example of a configuration change:
- Original: GF_INSTALL_PLUGINS: grafana-clock-panel,grafana-simple-json-datasource,natel-discrete-panel,grafana-piechart-panel
- Modified (Commented out for troubleshooting): #GF_INSTALL_PLUGINS: grafana-clock-panel...

For users with "J series" Synology NAS devices, there is a significant limitation: these models do not support Docker. In such instances, the containerized stack described in this guide is not an option. Administrators of J-series hardware must instead look toward non-containerized monitoring solutions such as Nagios or Zabbix, which can be installed via standard package managers or as standalone Linux services, though they lack the streamlined orchestration of a Docker-based Prometheus/Grafana stack.

Analytical Conclusion

The implementation of a Grafana and Prometheus stack on a Synology NAS is far more than a cosmetic upgrade to a system dashboard; it is a fundamental shift toward proactive infrastructure management. By leveraging the Docker/Container Manager ecosystem, an administrator transforms a passive storage device into an active, self-reporting node within a larger telemetry network.

The success of this deployment hinges on three critical pillars: strict filesystem persistence through volume mounting, precise network orchestration via firewall and SNMP configuration, and the continuous integration of specialized exporters like cAdvisor and Node Exporter. While the initial setup requires significant attention to detail—particularly regarding subnet masking for firewall rules and port mapping for service visibility—the long-term result is a resilient, high-fidelity monitoring environment. This environment provides the visibility necessary to preempt hardware failures, optimize resource allocation, and maintain the integrity of the data stored within the Synology ecosystem. As the complexity of modern home and small-business networks grows, the ability to visualize real-time trends and anomalies through a centralized, containerized observability layer becomes an indispensable skill for the modern technical professional.