Operating Systems for TAK Server on Raspberry Pi Deployments

September 2025

The Tactical Assault Kit (TAK)¹ is a situational awareness platform originating from defense use and adapted to civilian contexts. Mobile clients (ATAK for Android, WinTAK for Windows, iTAK for iOS) share positions, chat, video, and sensor data through encrypted channels. The TAK Server provides authentication, distributes geospatial layers, and brokers position updates, chat, and sensor feeds.

Building a reliable TAK deployment on Raspberry Pi hardware forces tradeoffs between OS maturity, driver availability, and long-term maintenance. Hardware choice is the Pi 4B, which offers the compute and memory needed for TAK server or multi-radio gateways, while the Pi Zero 2 W provides an inexpensive, power-efficient edge node. The more difficult decision lies in the operating system and radio drivers.

TAK server requirements

TAK server is built in Java, uses PostgreSQL for state, and is designed for multi-client concurrency. Recent builds support SQLite as an embedded store^[1]. It does not require exotic dependencies, but it benefits from stable memory management, predictable networking, and consistent update practices. A minimal setup may serve a handful of users, while larger deployments handle hundreds of concurrent clients relaying location and video data.

Clients can operate peer-to-peer without a server, but the server becomes the backbone for coordinated operations. It enforces authentication, certificates, and mission data distribution^[2]. A typical setup includes several Android or Windows clients, a server handling authentication and mission data, and optional gateways translating LoRa or HaLow radio networks into IP connectivity. On Raspberry Pi, the server role fits the Pi 4B (4 GB / 8 GB), while smaller boards like the Pi Zero 2 W are better suited to gateway functions that feed LoRa or HaLow traffic into the TAK network rather than hosting the server.

Operating system options

Debian (stable) provides a conservative base with long security coverage². The stable release line gets security fixes from the Debian Security Team, then extended support from the Debian LTS project for about five years on ARM platforms used by Raspberry Pi. Memory use is moderate: heavier than Raspberry Pi OS Lite but lighter than Ubuntu Server. Debian fits deployments that want reproducibility, minimal vendor policy (no snap pressure), and recent-enough runtimes for TAK server.

Ubuntu Server LTS targets general-purpose servers rather than appliance-style IoT images. On Raspberry Pi it offers five years of security updates, optional extended maintenance, and in-place upgrades between LTS releases via do-release-upgrade. Its package base includes current Java and PostgreSQL, which are ideal for TAK server, and most server tooling is still delivered as traditional apt packages rather than snaps. For operators who accept Canonical’s policies, Ubuntu Server LTS remains a practical choice when vendor-certified drivers, HaLow/LoRa SDKs, and integration with mainstream monitoring stacks matter more than strict distribution independence. Vendors targeting Linux almost always certify their drivers on Ubuntu first, making it a safe bet for HaLow and LoRa support. ^[3]

Ubuntu Core is a different product. It is a snap-only, image-based OS aimed at IoT appliances. The root filesystem is read-only, applications and system components are snaps, and updates are transactional with automatic rollback, all mediated through Canonical’s snap store. That model delivers rollback and predictable OTA behaviour, but it also ties packaging, signing, and long-term update control to Canonical infrastructure. For TAK deployments that prioritise owner-operated systems, offline rebuilds, and local package archives, Ubuntu Core pulls in the opposite direction of OpenWrt and Debian, aligning more with a vendor-managed appliance model than a field-serviceable platform.

Raspberry Pi OS Lite is lighter. It inherits Debian’s package stability, firmware tuning, and smaller memory footprint. For small nodes where efficiency matters more than modern package versions, it performs well. Long-term upgrade mechanics are rougher than Ubuntu’s—Debian dist-upgrades are possible but not always smooth, especially across kernel or firmware transitions.

OpenWrt fits a different role. Designed for routers, it has broad driver availability for radios and networking hardware. Its package ecosystem is slimmer and not oriented toward heavy application servers. It excels when the Pi is primarily a gateway, not when it needs to tap a wider software ecosystem³. Its upgrade path uses sysupgrade images, which are transactional and safe, but release support is shorter.

The table below contrasts the three main options across support, upgrade mechanics, driver ecosystem, and footprint.

OpenWrt and the SquashFS model

OpenWrt’s root filesystem is built on SquashFS, a compressed, read-only image mounted with a writable overlay (usually JFFS2 or F2FS). This design yields practical immutability:

• The base OS is read-only and immune to corruption.
• Factory reset simply erases the overlay.
• Upgrades replace the entire image atomically through sysupgrade.
• Failed upgrades automatically revert to the previous image.

That architecture makes OpenWrt inherently resilient under power loss, partial writes, or network failures. It is a closer analogue to transactional OS images used in aerospace and network appliances, but packaged for small ARM boards.

LoRa hardware and drivers

LoRa concentrators such as the Semtech SX1301/1302 families and modules from RAK or IMST integrate cleanly with Linux. Drivers expose interfaces over SPI or USB; higher-level stacks like ChirpStack provide Debian/Ubuntu packages with systemd units. Kernel support for the LoRaWAN subsystem has been present since Linux 4.19, so Ubuntu 24.04’s 6.8 kernel already has baseline support. On OpenWrt, packages exist but are tied to specific kernel builds. Pi OS Lite inherits the same drivers through Debian.

Wifi HaLow (802.11ah)

HaLow hardware is newer, but support is emerging. Vendors such as Morse Micro and ALFA distribute SDKs with Linux drivers and often target Debian/Ubuntu first. Out-of-tree kernel modules are common, with DKMS simplifying rebuilds after kernel updates. On OpenWrt, many HaLow evaluation kits ship with ready-to-flash images, useful for prototyping but less attractive for long-term server stability. Pi OS Lite behaves like Debian/Ubuntu but lags in kernel version, which can slow access to upstream fixes.

Interpreting the tradeoffs

OpenWrt’s SquashFS and atomic sysupgrade make it the most field-resilient of the three. It trades extensive package repositories for immutability and predictable recovery. With OpenJDK and SQLite, that trade is now mild. The system can act as a combined TAK Server + gateway image on a Pi 4B, or as a pure gateway on a Zero 2 W.

Debian/Ubuntu remains stronger for centralized infrastructure or high-density servers where integration, observability, and automation outweigh the need for a read-only base. Raspberry Pi OS retains its niche in minimal, manually managed systems or educational use.

For field-ready, distributed networks—nodes that are expected to run unattended, survive power loss, and update safely, OpenWrt now provides the cleanest operational model: immutable base, OTA upgrades, reproducible builds, and native support for both LoRa and HaLow drivers.

Why avoid Ubuntu and Canonical

Snap vs. traditional packaging

Canonical’s snap infrastructure centralizes software delivery under a single, closed-source store controlled by Canonical. Snaps require authentication and distribution through this store by default, preventing independent repositories from functioning as first-class citizens. This breaks the traditional decentralized Linux model—where anyone can host and sign packages—and ties updates, telemetry, and security patches to Canonical’s infrastructure. The store’s opaque review and signing processes make it impossible to reproduce or independently verify software provenance, creating a dependency that undermines both user autonomy and the core ideals of open-source distribution.

Licensing considerations

OpenWrt is the sane choice for IoT because it gives developers full control, reproducibility, and independence, while Canonical’s Ubuntu Core is effectively a closed ecosystem disguised as open source. Ubuntu’s snap infrastructure centralizes power under Canonical, enforcing signed images, opaque update channels, and licensing maneuvers that strip users of modification rights in the name of “security”. The push toward MIT-licensed rewrites and mandatory snaps reflects a corporate strategy to neutralize GPL reciprocity and lock integrators into Canonical’s infrastructure. OpenWrt, by contrast, remains transparent, rebuildable, and community-governed. A system you can actually own rather than lease from a vendor masquerading as an open-source partner.

Long-term considerations

Partial immutability is achievable regardless of OS. Ubuntu and Pi OS Lite support overlayroot for read-only root with selective writable paths, containerization for service isolation, and snapshotting on filesystems like btrfs. OpenWrt’s sysupgrade mechanism already delivers transactional upgrades. For appliance-like radio nodes, OpenWrt’s simplicity wins.

The operating system choice reflects deployment role: TAK server vs. radio gateway. For resilient Raspberry Pi deployments, OpenWrt is the default starting point, with Debian reserved for heavier central servers. Teams building TAK infrastructure should avoid handing control of update policy, package trust, and runtime tooling to Canonical, because that introduces a single corporate gatekeeper into systems that are supposed to be sovereign, field-serviceable, and owner-operated.