iDRAC Fan Speed Control

Dell PowerEdge 伺服器風扇控制工具。它透過 iDRAC/IPMI raw command 設定風扇轉速，並可依 ESXi NVMe SMART、iDRAC temperature sensors、NVIDIA GPU 溫度自動調整。

Safety first: 這個專案會覆寫 Dell 原廠風扇控制。設定錯誤可能讓硬體過熱。第一次使用請在旁監看溫度、保留 iDRAC Web UI 存取權，並確認 restore 指令可用。

What It Does

auto: 持續讀取溫度，依 fan curve 設定風扇。
once: 執行一次溫度讀取與風扇調整後離開。
manual: 手動設定 1-100% 風扇 duty cycle。
restore: 將 iDRAC 還原為 Dell 自動風扇控制。
status: 印出 iDRAC chassis status 與 temperature sensors。
validate: 檢查本機設定是否足以啟動目前模式。

Improvements In This Version

溫度來源可選 esxi、idrac、gpu，也可混用。
溫度讀取失敗時套用 FAILSAFE_FAN_SPEED，不再掉到最低風扇轉速。
支援 hysteresis，避免溫度卡在閾值附近時風扇反覆跳速。
支援 ESXi SSH password 或 key authentication。
IPMI 密碼改用 IPMI_PASSWORD environment 傳給 ipmitool -E，避免出現在 command line。
舊手動腳本已改成 wrapper，共用同一份核心邏輯。
新增 make test、Docker healthcheck、.dockerignore、.gitignore、MIT LICENSE。

Requirements

Requirement	Why
Dell PowerEdge with iDRAC	送出 IPMI fan raw commands
iDRAC IPMI over LAN enabled	`ipmitool -I lanplus` 需要 LAN access
Docker / Docker Compose	建議部署方式
ESXi SSH access	只有 `TEMPERATURE_SOURCES` 包含 `esxi` 時需要
NVIDIA Container Toolkit	只有 `gpu` 溫度來源需要

Tested target: Dell PowerEdge R730xd/R730XD class servers with iDRAC 8. Other Dell models may support the same OEM raw commands, but you should test with manual and restore before running unattended.

Quick Start

Clone the repository.

git clone https://github.com/DF-wu/iDRACFanSpeedControl.git
cd iDRACFanSpeedControl

Create a private environment file.

cp .env.example .env
chmod 600 .env

Edit .env.

Minimum iDRAC-only auto mode:

IDRAC_IP=192.0.2.10
IDRAC_ID=root
IDRAC_PASSWORD=change-me
OPERATION_MODE=auto
TEMPERATURE_SOURCES=idrac

ESXi NVMe SMART mode:

TEMPERATURE_SOURCES=esxi
ESXI_HOST=192.0.2.20
ESXI_USERNAME=root
ESXI_PASSWORD=change-me
DRIVE_DEVICE=t10.NVMe____replace_with_your_device_identifier

Validate and start.

docker compose run --rm idrac-fan-control validate
docker compose up -d
docker logs -f idrac-fan-control

Restore Dell automatic control when needed.

docker compose run --rm idrac-fan-control restore

Commands

Docker Compose passes extra arguments to the container entrypoint:

# Run continuously according to OPERATION_MODE=auto
docker compose up -d

# Run one automatic cycle
docker compose run --rm idrac-fan-control once

# Set manual fan speed to 35%
docker compose run --rm idrac-fan-control manual 35

# Restore Dell automatic fan control
docker compose run --rm idrac-fan-control restore

# Print chassis and temperature sensor status
docker compose run --rm idrac-fan-control status

# Validate config without touching fan speed
docker compose run --rm idrac-fan-control validate

Local script usage is the same:

src/FanControlWithEsxiSmart.sh manual 35
src/FanControlWithEsxiSmart.sh restore

Temperature Sources

TEMPERATURE_SOURCES accepts comma-separated values.

Source	Reads	Requires
`esxi`	One NVMe drive's SMART temperature through `esxcli`	ESXi SSH, `DRIVE_DEVICE`
`idrac`	iDRAC temperature sensors from `ipmitool sdr type Temperature`	iDRAC credentials
`gpu`	NVIDIA GPU temperature from `nvidia-smi`	NVIDIA Container Toolkit

Hybrid mode uses the highest decision temperature:

decision_temperature = max(esxi_temp, idrac_sensor_temps..., gpu_temp - GPU_TEMP_OFFSET)

Examples:

# No ESXi dependency. Use iDRAC sensors only.
TEMPERATURE_SOURCES=idrac

# NVMe SMART plus iDRAC ambient/CPU sensors.
TEMPERATURE_SOURCES=esxi,idrac

# NVMe SMART plus GPU compensation.
TEMPERATURE_SOURCES=esxi,gpu
GPU_TEMP_OFFSET=15

# Backward-compatible switch. This appends gpu to TEMPERATURE_SOURCES.
WITH_GPU_TEMP=true

Fan Curve

The controller maps the decision temperature to a fan level.

Level	Temperature range	Default speed
`idle`	`< TEMP_LOW`	`FAN_SPEED_IDLE=25`
`low`	`TEMP_LOW` to `< TEMP_MEDIUM`	`FAN_SPEED_LOW=30`
`medium`	`TEMP_MEDIUM` to `< TEMP_HIGH`	`FAN_SPEED_MEDIUM=40`
`high`	`TEMP_HIGH` to `< TEMP_CRITICAL`	`FAN_SPEED_HIGH=50`
`critical`	`>= TEMP_CRITICAL`	`FAN_SPEED_CRITICAL=60`
`failsafe`	all temperature sources failed	`FAILSAFE_FAN_SPEED=70`

Default thresholds:

TEMP_LOW=65
TEMP_MEDIUM=70
TEMP_HIGH=75
TEMP_CRITICAL=80
HYSTERESIS=2

Hysteresis only delays downshifts. For example, if the current level is high and TEMP_HIGH=75, the controller keeps high until the temperature falls to 73C or lower when HYSTERESIS=2.

Configuration Reference

Variable	Default	Notes
`IDRAC_IP`	empty	Required for all fan commands
`IDRAC_ID`	`root`	iDRAC username
`IDRAC_PASSWORD`	empty	iDRAC password
`IPMI_INTERFACE`	`lanplus`	Usually keep this value
`IPMI_TIMEOUT`	`5`	Seconds per IPMI attempt
`IPMI_RETRIES`	`2`	IPMI retry count
`OPERATION_MODE`	`manual`	`auto`, `once`, or `manual`
`TEMPERATURE_SOURCES`	`esxi`	Comma-separated: `esxi,idrac,gpu`
`WITH_GPU_TEMP`	`false`	Backward-compatible GPU switch
`GPU_TEMP_OFFSET`	`15`	Subtracted from GPU temperature
`CHECK_INTERVAL`	`60`	Seconds between auto cycles
`COMMAND_TIMEOUT`	`20`	Wrapper timeout for SSH, IPMI, and GPU reads
`ESXI_HOST`	empty	Required when source includes `esxi`
`ESXI_USERNAME`	`root`	ESXi SSH username
`ESXI_PASSWORD`	empty	Use password auth when `ESXI_SSH_KEY` is empty
`ESXI_SSH_KEY`	empty	Optional SSH private key path
`ESXI_SSH_PORT`	`22`	ESXi SSH port
`SSH_CONNECT_TIMEOUT`	`10`	SSH connection timeout
`DRIVE_DEVICE`	empty	ESXi NVMe device identifier
`TEMP_LOW`	`65`	Idle to low threshold
`TEMP_MEDIUM`	`70`	Low to medium threshold
`TEMP_HIGH`	`75`	Medium to high threshold
`TEMP_CRITICAL`	`80`	High to critical threshold
`FAN_SPEED_IDLE`	`25`	Fan speed below `TEMP_LOW`
`FAN_SPEED_LOW`	`30`	Fan speed at low level
`FAN_SPEED_MEDIUM`	`40`	Fan speed at medium level
`FAN_SPEED_HIGH`	`50`	Fan speed at high level
`FAN_SPEED_CRITICAL`	`60`	Fan speed at critical level
`HYSTERESIS`	`2`	Degrees C before downshift
`FAILSAFE_ON_ERROR`	`true`	Apply fail-safe when all sources fail
`FAILSAFE_FAN_SPEED`	`70`	Conservative speed for sensor failure
`RESTORE_AUTO_ON_EXIT`	`true`	Restore Dell auto control when auto mode exits
`MANUAL_FAN_SPEED`	empty	Used by `manual` mode without an argument
`LOG_DIR`	`/var/log/fan-control`	Set empty only for tests
`LOG_FILE`	`fan_control.log`	Status log file name
`DRY_RUN`	`false`	Log commands without running `ipmitool`

Getting The ESXi Drive Identifier

SSH to the ESXi host and list storage devices:

ssh root@192.0.2.20
esxcli storage core device list

Find the NVMe device ID and test SMART temperature output:

esxcli storage core device smart get -d t10.NVMe____replace_with_your_device_identifier

Use that full ID as DRIVE_DEVICE.

GPU Mode

Install NVIDIA Container Toolkit on the Docker host, then enable GPU access in docker-compose.yml:

gpus: all

Set one of these in .env:

TEMPERATURE_SOURCES=esxi,gpu
# or
WITH_GPU_TEMP=true

Verify GPU access:

docker run --rm --gpus all nvidia/cuda:12.9.0-runtime-ubuntu24.04 nvidia-smi
docker compose run --rm idrac-fan-control status

Logs

Container logs show control decisions:

docker logs -f idrac-fan-control

Persistent fan-control logs are written to ./logs/fan_control.log by the Compose volume:

tail -f logs/fan_control.log

Each line includes status, temp, level, fan, and source details.

Testing

Run local tests:

make test

The tests cover:

Bash syntax checks.
Temperature source normalization.
iDRAC sensor parsing.
GPU offset decision logic.
Fan curve and hysteresis behavior.
Fail-safe behavior when every source fails.
Validation for iDRAC-only auto mode.

Run a dry validation target:

make validate

Build a local image:

make docker-build

If you do not need GPU support, build with a smaller Ubuntu base:

docker build --build-arg BASE_IMAGE=ubuntu:24.04 -t idrac-fan-control:local .

Troubleshooting

`validate` says iDRAC config is missing

Set IDRAC_IP, IDRAC_ID, and IDRAC_PASSWORD in .env. Also confirm IPMI over LAN is enabled in iDRAC.

ipmitool -I lanplus -H "$IDRAC_IP" -U "$IDRAC_ID" -P "$IDRAC_PASSWORD" chassis status

Auto mode fails because ESXi is missing

If you do not want ESXi SSH, use iDRAC sensors:

TEMPERATURE_SOURCES=idrac

If you want ESXi SMART temperature, set ESXI_HOST, ESXI_USERNAME, ESXI_PASSWORD or ESXI_SSH_KEY, and DRIVE_DEVICE.

Temperature reads fail and fans jump to fail-safe

That is intentional. The controller uses FAILSAFE_FAN_SPEED when no temperature source succeeds. Check the source-specific logs, then test each dependency:

docker compose run --rm idrac-fan-control status
ssh root@your-esxi-host
nvidia-smi

Manual mode works, but auto mode is too noisy

Raise the fan curve or add hysteresis:

TEMP_LOW=70
TEMP_MEDIUM=75
TEMP_HIGH=80
TEMP_CRITICAL=85
HYSTERESIS=3

Restore automatic control

Run:

docker compose run --rm idrac-fan-control restore

This sends:

raw 0x30 0x30 0x01 0x01

Security Notes

Keep .env private. This repository now ignores .env; if your clone still tracks it, run git rm --cached .env.
Prefer a dedicated iDRAC account if your iDRAC version supports suitable privileges.
Keep iDRAC and ESXi on a management network, not a public network.
Prefer ESXI_SSH_KEY over password auth when possible.
Review logs after every fan curve change.

Repository Layout

.
├── src/
│   ├── FanControlWithEsxiSmart.sh   # main entrypoint
│   └── setIdracFanSpeed.sh          # backward-compatible manual wrapper
├── tests/
│   └── fan-control.test.sh          # shell tests with mocked behavior
├── images/
│   └── image.png                    # iDRAC IPMI over LAN screenshot
├── .env.example                     # documented configuration template
├── docker-compose.yml
├── Dockerfile
├── Makefile
└── README.md

Roadmap

Add structured metrics output for Prometheus or node exporters.
Add optional fan ramping for smoother transitions.
Add log rotation examples for long-running hosts.
Add model-specific notes for more Dell PowerEdge generations.

License

MIT. See LICENSE.

Last reviewed: 2026-06-08.

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Repository files navigation

iDRAC Fan Speed Control

What It Does

Improvements In This Version

Requirements

Quick Start

Commands

Temperature Sources

Fan Curve

Configuration Reference

Getting The ESXi Drive Identifier

GPU Mode

Logs

Testing

Troubleshooting

`validate` says iDRAC config is missing

Auto mode fails because ESXi is missing

Temperature reads fail and fans jump to fail-safe

Manual mode works, but auto mode is too noisy

Restore automatic control

Security Notes

Repository Layout

Roadmap

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.github/workflows		.github/workflows
images		images
src		src
tests		tests
.dockerignore		.dockerignore
.env.example		.env.example
.gitignore		.gitignore
Dockerfile		Dockerfile
LICENSE		LICENSE
Makefile		Makefile
README.md		README.md
USAGE_GUIDE.md		USAGE_GUIDE.md
docker-compose.yml		docker-compose.yml

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iDRAC Fan Speed Control

What It Does

Improvements In This Version

Requirements

Quick Start

Commands

Temperature Sources

Fan Curve

Configuration Reference

Getting The ESXi Drive Identifier

GPU Mode

Logs

Testing

Troubleshooting

validate says iDRAC config is missing

Auto mode fails because ESXi is missing

Temperature reads fail and fans jump to fail-safe

Manual mode works, but auto mode is too noisy

Restore automatic control

Security Notes

Repository Layout

Roadmap

License

About

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