MD12xx Fan Control for Unraid

Standalone, host-native fan control for Dell PowerVault MD1200 and MD1220 disk shelves.

Beta: MD1200 control and SES telemetry have been verified on real hardware. MD1220 uses the same Dell MD12xx enclosure family and is included for testing, but its serial fan response still requires independent hardware confirmation.

Hardware status

Reports from different HBAs, firmware revisions, serial adapters, and Unraid releases are wanted. Use the repository's Beta hardware report issue form and remove unique identifiers before posting.

Requirements

• Unraid 7.3.2 or newer. This is the oldest release validated by the current beta.
• A Dell PowerVault MD1200, or an MD1220 for experimental validation. MD1400, MD1420, and other shelves are not supported by this release.
• A compatible SAS HBA/controller and external SAS cabling that expose both the enclosure's disks and a SCSI Enclosure Services device under /dev/sg* to Unraid.
• sg_ses available on the Unraid host.
• Access to the active/primary EMM console through a persistent /dev/serial/by-id path. The tested MD1200 command path uses a Dell-compatible six-pin service/password-reset cable, an FTDI USB-to-serial adapter, and the required USB cable to the server. Other adapter chipsets are unverified.
• Matching firmware on both EMMs is strongly recommended.
• Exclusive fan control: Docker containers, scripts, and other plugins that write to the same serial console must be stopped.

The plugin discovers candidates and proves each serial-to-SES pairing with a guarded RPM test. It does not assume that a USB adapter, model string, disk count, or path belongs to a particular shelf.

The command and verification paths are intentionally independent:

Fan commands: Unraid USB -> FTDI adapter -> Dell service cable -> active EMM console
Verification: Unraid -> SAS HBA/controller -> enclosure SES interface

The plugin reads SES enclosure status through the HBA; it does not configure or flash the HBA, change RAID settings, or send fan commands through SAS. Disk temperatures and spin state come from Unraid's existing /var/local/emhttp/disks.ini state rather than direct SMART polling by this plugin.

MD1200 hardware validation currently covers the tested direct-attached arrangements described in the hardware reports. Split mode, daisy chains, redundant paths, alternate EMM layouts, and MD1220 hardware remain Beta test cases unless a report explicitly proves them.

Features

• Supports one or more MD1200/MD1220 shelves.
• Passively inventories candidate SES devices, persistent serial adapter paths, and Unraid disks.
• Automatically maps the shelf's current Unraid disk names through standard enclosure links or the verified SES device's exact SAS expander.
• Optionally verifies likely FTDI serial consoles with a read-only _who query while all fan controllers are stopped.
• Auto mode controls each shelf from its assigned disks independently.
• Manual choices from 20% through 100% in 10% increments.
• Reads independent fan RPM telemetry through sg_ses.
• Saves each shelf's commissioned 20%/50% RPM response and verifies later control commands against independent SES telemetry.
• Uses stable SCSI addresses and /dev/serial/by-id paths.
• Uses carriage-return-only BlueDress set_speed command framing confirmed on MD1200 hardware.
• Blocks writes while the legacy MD1200-Fan-Controller Docker is running.
• Starts disabled and requires explicit configuration and commissioning.
• Retains settings during normal plugin updates. Uninstall deliberately removes configuration and commissioning results so reinstall starts clean.
• Supervises the controller process, restarts unexpected exits with bounded backoff, and sends local Unraid failure and recovery notifications.

Default Auto curve

The controller polls every 5 seconds, uses 1°C downshift hysteresis, and reasserts the target every 15 minutes. Saved control changes wake the controller immediately rather than waiting for the next telemetry poll. After a command, the controller waits for independent SES telemetry to match the commissioned response; failure becomes a visible fault and triggers a guarded retry. Continued telemetry drift is also detected. Commands above 50% can prove at least the commissioned 50% response, but their exact RPM remains uncalibrated.

The Settings page supports between 2 and 10 Auto-curve points. Temperatures must increase, and fan speeds may stay level or increase as temperature rises.

Safety model

The normal setup asks for one verified persistent serial adapter. The guarded identification test first repeats the read-only MD12xx console check, then measures every candidate SES enclosure at 20% and 50%. It accepts the pairing only when exactly one enclosure shows a clear RPM response, automatically maps that enclosure's Linux block devices to the current Unraid disk names, and refuses to commission until independent SES telemetry proves the final 20% restoration. Mapping uses standard enclosure-slot links when available and otherwise requires the disks to share the verified SES device's exact SAS expander. If neither relationship is available, the Settings page retains an explicit Manual mapping fallback.

The plugin does not treat a matching model name, USB vendor, prompt string, or drive count as proof of a serial-to-SES pairing. Ambiguous RPM results and empty automatic disk assignments are not commissioned. If the commissioned disk mapping changes or assigned disks disappear from Unraid's inventory, Auto mode selects the configured fail-safe speed instead of assuming the disks are asleep. Changing a shelf's model, serial adapter, SES pairing, assignment mode, or disk list clears commissioning and requires a new test.

If commissioning cannot prove the final 20% state, the shelf remains uncommissioned and the controller must remain disabled. Keep competing fan writers stopped and use Identify & test again; each retry begins by commanding 20%. If another attempt still cannot verify the restoration, stop setup, leave the shelf uncommissioned, restore a known-safe state using the enclosure's previously proven control method, and attach reviewed diagnostics to a support report.

Active connection discovery is off by default and automatically turns off once every configured shelf has passed commissioning. It can be enabled again manually for troubleshooting. When enabled, it considers a console verified only when the structured MD12xx _who response and the primary/active EMM role are both present. BlueDress is recorded when seen but is not required, because prompt wording may differ by firmware. Discovery never sends set_speed and pauses whenever this or another fan controller is active.

Do not run this plugin alongside another process that writes to the same enclosure serial adapter. The controller, discovery worker, and commissioning test also refuse to open a serial device that the operating system reports as already in use.

Install and setup

Download the published plugin manifest and install it through Plugins → Install Plugin, or use:

wget -O /tmp/md12xx.fancontrol.plg \
  'https://raw.githubusercontent.com/TheIlluminate92/unraid-md12xx-fan-control/main/releases/md12xx.fancontrol.plg'
plugin install /tmp/md12xx.fancontrol.plg

The WebGUI installer requires a current authenticated Unraid session and a valid CSRF token. If Install only clears the URL and the system log records no plugin-manager attempt, reconnect through the server's direct local WebGUI and sign in again; remote or proxied sessions that do not expose the Unraid token cannot submit the native installer form. This failure occurs before the plugin URL is downloaded.

Open Settings → Utilities → MD12xx Fan Control, expand Setup directions, and leave the controller disabled until every shelf passes Identify & test. The app shows live progress for the guarded 20% → 50% → 20% test and continues the server-side safety workflow if the page is closed. Refresh discovery saves only the discovery options and runs one guarded inventory pass immediately. Active FTDI testing is a temporary setup tool and turns off after every configured shelf is commissioned.

If discovery identifies the selected console but reports that it is not the active/primary EMM, move the service connection to the active EMM and refresh discovery before commissioning. Do not bypass that identity check.

Screenshots

Normal updates keep configuration. Uninstall is a complete reset: it removes /boot/config/plugins/md12xx.fancontrol, including saved shelf mappings, local diagnostics, and commissioning results, as well as runtime files and state. Copy anything you want to retain before uninstalling.

Development

Build dist/md12xx.fancontrol.plg, copy it to the Unraid boot flash, then install it through Plugins → Install Plugin. Configure it under Settings → Utilities → MD12xx Fan Control.

Run bash tests/verify.sh on Linux before publishing. The suite builds the package, validates runtime syntax, exercises MD1200 and synthetic 24-bay MD1220 fixtures, checks the safety markers, and runs the local-only security policy scan.

Privacy and diagnostics

Export local diagnostics creates and downloads a redacted archive from /boot/config/plugins/md12xx.fancontrol/diagnostics. It does not upload anything. Review the archive before sharing it, then use Report issue on GitHub to open the public issue form and attach the archive yourself. Files attached to this public repository can be accessed without authentication. See SECURITY.md for the exact read/write and network boundaries.

The plugin intentionally does not authenticate to GitHub or upload diagnostics automatically. That keeps repository credentials off the server and leaves the final privacy decision with the operator.

Development transparency

This is an AI-assisted open-source project. Erik Boettcher / TheIlluminate92 owns the project and provides product direction, the original Docker prototype, hardware access, safety decisions, physical testing, and release approval. OpenAI Codex (GPT-5) provided primary implementation assistance for the standalone plugin, including architecture, code generation, tests, documentation, packaging, and debugging, under Erik's direction and review. See ACKNOWLEDGEMENTS.md for the complete credits.

Status integration

Other local plugins and authenticated Unraid WebGUI modules can read:

/plugins/md12xx.fancontrol/include/api.php

The default GET response is read-only JSON containing controller, watchdog, and per-shelf state. The supported Beta integration surface also includes a CSRF-protected Auto/Manual control action; setup and commissioning actions remain WebGUI-internal.

See the local API reference for request examples, response fields, error handling, polling guidance, authentication requirements, and the local-only security boundary.

License and hardware disclaimer

MIT licensed. Dell does not document the BlueDress fan command used by this project. Use at your own risk, keep current backups, and validate every shelf before enabling automatic control.

See ACKNOWLEDGEMENTS.md for project credits, CONTRIBUTING.md for safe hardware reports and development rules, and RELEASE_CHECKLIST.md for the remaining Beta/Community Apps gates.