Supermicro Fan Control

.bash_aliases

alias fan-auto='systemctl start supermicro-fan-auto.timer'
alias fan-full='systemctl stop supermicro-fan-auto.timer && sleep 5 && sm fan full'
alias fan-pue2='systemctl stop supermicro-fan-auto.timer && sleep 5 && sm fan pue2'
alias fan-optimal='systemctl stop supermicro-fan-auto.timer && sleep 5 && sm fan optimal'
alias fan-heavyio='systemctl stop supermicro-fan-auto.timer && sleep 5 && sm fan heavyio'
alias fan-standard='systemctl stop supermicro-fan-auto.timer && sleep 5 && sm fan standard'

README.md

Rules-based fan control for Supermicro boards. Tested at A2SDi+8C+-HLN4F.

Note: PUE2 is not supported at some Supermicro boards! Change DEFAULT_FANMODE if required.

apt install ipmitool

mkdir -p /var/cache/ipmi/sdr
ipmitool sdr dump /var/cache/ipmi/sdr/local
ln -s supermicro /usr/local/sbin/sm

editor \
  /usr/local/sbin/supermicro \
  /usr/local/etc/supermicro.cfg \
  /etc/systemd/system/supermicro-fan.service \
  /etc/systemd/system/supermicro-fan-auto.service \
  /etc/systemd/system/supermicro-fan-auto.timer

systemctl daemon-reload
systemctl enable supermicro-fan.service
systemctl start supermicro-fan

# Optional: Update fan speed by temperature
systemctl enable --now supermicro-fan-auto.timer

crontab

# OPTIONAL: Cronjob
0 10 * * * root if [ ! -e "/tmp/.disable-supermicro-cronjob" ]; then /usr/bin/systemctl stop supermicro-fan-auto.timer && /usr/bin/sleep 30 && /usr/local/sbin/supermicro fan heavyio >/dev/null; fi
0 22 * * * root if [ ! -e "/tmp/.disable-supermicro-cronjob" ]; then /usr/bin/systemctl start supermicro-fan-auto.timer; fi

supermicro

#!/bin/bash
set -euf -o pipefail

IPMITOOL_ARGS=()
DEFAULT_FANMODE="optimal"
DEFAULT_FANSPEED=( 100 100 )
DEFAULT_FANSLEEP=5
AUTOFAN_SOURCES=()
AUTOFAN_PENALTY=()
AUTOFAN_BASE=()
AUTOFAN_MIN=()
AUTOFAN_MAX=()

# Optional: Override configuration vars
if [[ -f /usr/local/etc/supermicro.cfg ]]
then
	#shellcheck disable=SC1091
	source /usr/local/etc/supermicro.cfg
fi

function argc
{
	if [[ "$1" -lt "$2" ]]
	then usage
	fi
}

function usage
{
	cat << EOF >&2
Usage: $0 <COMMAND> [<ARGS> ...]

  Display current fan settings:
       $0 fan

  Update fan settings:
       $0 fan standard|optimal|pue[2]|heavy[io]
       $0 fan full [<PERCENT> ...]
       $0 fan default

  Adjust fan settings based on sensor temperatures:
       $0 fan auto
EOF
	exit 1
}

function stderr
{
	printf '%s\n' "$@" 1>&2
}

function intval
{
	local i

	i=${1//[[:space:]]}
	i=${i#"${i%%[!0]*}"}

	printf '%d' "$i" 2>/dev/null || :
}

function hex2int
{
	printf '%d' "0x${1//[[:space:]]}" 2>/dev/null || :
}

function int2hex
{
	printf '0x%02x' "$1"
}

function execIPMI
{
	ipmitool -c "${IPMITOOL_ARGS[@]}" "$@"
}

function sendRawCommand
{
	execIPMI raw "$@" | sed '/./,$!d'
}

function getFanModeName
{
	local name="Standard"

	case "$1" in
		1) name="Full"    ;;
		2) name="Optimal" ;;
		3) name="PUE2"    ;;
		4) name="HeavyIO" ;;
	esac

	printf '%s' "$name"
}

function getFanModeKey
{
	getFanModeName "${1,,}"
}

function getFanModeID
{
	local -i fanmode=0

	case "${1,,}" in
		full)      fanmode=1 ;;
		optimal)   fanmode=2 ;;
		pue*)      fanmode=3 ;;
		heavy*|io) fanmode=4 ;;
	esac

	printf '%d' "$fanmode"
}

function getFanMode
{
	hex2int "$(sendRawCommand 0x30 0x45 0x00)"
}

function setFanMode
{
	local -i fanmode
	local -i current
	local hex

	fanmode=$(getFanModeID "$1")
	current=$(getFanMode)

	if (( current != fanmode ))
	then
		hex=$(int2hex "$fanmode")
		stderr "Setting new fan mode: $hex ($(getFanModeName "$fanmode"))"
		sendRawCommand 0x30 0x45 0x01 "$hex"

		if [[ "$fanmode" -eq "$(getFanModeID "full")" ]]
		then
			sleep "$DEFAULT_FANSLEEP"
		fi
	else
		stderr "Current fan mode not changed: $(int2hex "$current") ($(getFanModeName "$current"))"
	fi
}

function getFanSpeed
{
	hex2int "$(sendRawCommand 0x30 0x70 0x66 0x00 "$(int2hex "$1")")"
}

function setFanSpeed
{
	local zone
	local value

	zone=$(int2hex "$1")
	value=$(int2hex "$2")

	stderr "Setting fan speed of zone $zone: $value ($2%)"
	sendRawCommand 0x30 0x70 0x66 0x01 "$zone" "$value"
}

function loadTemperatureValues
{
	local result k v
	result=$(execIPMI sdr type Temperature)
	declare -g -A temperatureValues

	while IFS=',' read -r k v _
	do
		k=${k,,}
		k=${k/% */}
		k=${k/%[a-z][0-9]/}
		v=$(intval "$v")

		if [[ -z "${temperatureValues[$k]-}" || "${temperatureValues[$k]}" -lt "$v" ]]
		then
			temperatureValues[$k]="$v"
		fi
	done <<< "$result"

	for k in "${AUTOFAN_SOURCES[@]}"
	do
		k=${k,,}
		k=${k/% */}
		k=${k/%[a-z][0-9]/}
		v=$("smCustomSource${k^^}" ||:)
		v=$(intval "$v")

		if [[ -z "${temperatureValues[$k]-}" || "${temperatureValues[$k]}" -lt "$v" ]]
		then
			temperatureValues[$k]="$v"
		fi
	done
}

function processFanSpeedRules
{
	local mode
	mode=$1
	shift

	local key
	key=$1
	shift

	local -i value
	value=$(intval "$1")
	shift

	for line in "$@"
	do
		IFS=" " read -r sensor temperature zones <<< "$line"
		temperature=$(intval "$temperature")
		sensor=${sensor,,}

		if [[ "$sensor" == "$key" ]]
		then
			if [[ "$mode" == "min" && "$value" -le "$temperature" ]] || [[ "$mode" == "max" && "$value" -ge "$temperature" ]]
			then
				if [[ "$mode" == "min" && -n "${AUTOFAN_BASE[*]-}" ]]
				then saveFanSpeedZones "${AUTOFAN_BASE[*]}"
				else saveFanSpeedZones "$zones"
				fi

				fanSpeedFixed=1
				return
			fi

			printf -v "fanSpeed${mode^}Temp" '%s' "$temperature"
			read -r -a "fanSpeedZones${mode^}" <<< "$zones"
			return
		fi
	done
}

function saveFanSpeedZones
{
	local -i i; i=0
	for speed in $1
	do
		if [[ "$speed" -gt 0 ]] && [[ -z "${fanSpeedZones[$i]-}" || "${fanSpeedZones[$i]}" -lt "$speed" ]]
		then
			saveFanSpeedZone "$i" "$speed"
		fi

		i=$(( i + 1 ))
	done
}

function saveFanSpeedZone
{
	fanSpeedZones[$1]=$2
	fanSpeedChanged=1
}

function adjustFanSpeeds
{
	declare -g -i fanSpeedFixed
	declare -g -A fanSpeedZones
	declare -g -a fanSpeedZonesMin
	declare -g -a fanSpeedZonesMax
	declare -g -i fanSpeedChanged
	declare -g -i fanSpeedPenalty
	declare -i fanSpeedMinTemp
	declare -i fanSpeedMaxTemp
	local -i time
	local -i percent
	local -i value
	local -i start
	local -i end
	local final
	local dow
	local s
	local e

	fanSpeedPenalty=100
	time=$(intval "$(date +%H%M)")
	for rule in "${AUTOFAN_PENALTY[@]}"
	do
		IFS=" " read -r dow s e percent final <<< "$rule"
		start=$(intval "$s")
		end=$(intval "$e")

		if [[ "$dow" != "*" ]]
		then
			dow=$(intval "$dow")

			if [[ "$dow" -ne "$(date +%u)" && "$dow" -ne "$(date +%w)" ]]
			then
				continue
			fi
		fi

		if [[ "$end" -lt "$start" && "$time" -le "$end" ]] \
		|| [[ "$end" -lt "$start" && "$time" -ge "$start" ]] \
		|| [[ "$time" -ge "$start" && "$time" -le "$end" ]]
		then
			fanSpeedPenalty=$(intval "$percent")

			if [[ -n "$final" ]]
			then
				break
			fi
		fi
	done

	fanSpeedChanged=0
	loadTemperatureValues

	for key in "${!temperatureValues[@]}"
	do
		value=${temperatureValues[$key]}

		fanSpeedZonesMin=()
		fanSpeedZonesMax=()
		fanSpeedMinTemp=0
		fanSpeedMaxTemp=0
		fanSpeedFixed=0

		processFanSpeedRules min "$key" "$value" "${AUTOFAN_MIN[@]}"
		processFanSpeedRules max "$key" "$value" "${AUTOFAN_MAX[@]}"

		if [[ "$fanSpeedFixed" -ne 1 ]]
		then
			c1=$(intval "${#fanSpeedZonesMin[@]}")
			c2=$(intval "${#fanSpeedZonesMax[@]}")
			c=$(( c1 > c2 ? c1 : c2 ))

			for (( i=0; i < c; i++ ))
			do
				minSpeed=$(intval "${fanSpeedZonesMin[$i]-0}")
				maxSpeed=$(intval "${fanSpeedZonesMax[$i]-0}")

				if [[ "$minSpeed" -gt 0 && "$maxSpeed" -gt 0 ]]
				then
					speed=$(bc -l <<< "result = ($maxSpeed - $minSpeed) / 100 * (100 / (($fanSpeedMaxTemp - $fanSpeedMinTemp) / ($value - $fanSpeedMinTemp))) + $minSpeed; scale=0; result/1")

					if [[ "$speed" -gt 0 ]] && [[ -z "${fanSpeedZones[$i]-}" || "${fanSpeedZones[$i]}" -lt "$speed" ]]
					then
						saveFanSpeedZone "$i" "$speed"
					fi
				fi
			done
		fi
	done

	if (( fanSpeedChanged ))
	then
		setFanMode "full"
		for key in "${!fanSpeedZones[@]}"
		do
			value=$(bc -l <<< "result = ${fanSpeedZones[$key]-0} / 100 * $fanSpeedPenalty; if ( result < 1 ) result=1; scale=0; result/1")
			value=$(( value > 100 ? 100 : value ))

			if  [[ "$value" -gt 0 ]]
			then
				setFanSpeed "$key" "$value"
			fi
		done
	fi
}

argc $# 1
MODE=${1,,}
shift

case "$MODE" in

	fan)
		if [[ "$#" -eq 0 ]]
		then
			mode=$(getFanMode)
			echo "Current fan mode: $(int2hex "$mode") ($(getFanModeName "$mode"))"

			c=${#DEFAULT_FANSPEED[@]}
			for (( i=0; i < c; i++ ))
			do
				speed=$(getFanSpeed "$i")
				echo "Fan speed of zone $(int2hex "$i"): $(int2hex "$speed") ($speed%)"
			done

			exit 0
		fi

		#argc $# 1
		mode=${1,,}

		if [[ "$mode" == "default" ]]
		then
			setFanMode "$DEFAULT_FANMODE"
			exit $?
		elif [[ "$mode" == "auto" ]]
		then
			adjustFanSpeeds
			exit $?
		fi

		fanmode=$(getFanModeID "$mode")
		setFanMode "$(getFanModeKey "$fanmode")"
		shift

		if [[ "$fanmode" -eq $(getFanModeID "full") ]]
		then
			FANZONES=( "$@" )
			c=$(( ${#FANZONES[@]} - 1 ))

			if (( c >= 0 ))
			then
				for (( i=0; i <= c; i++ ))
				do
					v=$(intval "${FANZONES[i]}")

					if (( v > 0 ))
					then
						setFanSpeed "$i" "${FANZONES[i]}"
					fi
				done
			else
				c=$(( ${#DEFAULT_FANSPEED[@]} - 1 ))
				for (( i=0; i <= c; i++ ))
				do
					setFanSpeed "$i" "${DEFAULT_FANSPEED[i]}"
				done
			fi
		fi
		;;

	*)
		usage
		;;
esac

supermicro-fan-auto.service

[Unit]
Description=Supermicro Auto Fan Mode (Service)
Requires=openipmi.service
After=openipmi.service

[Service]
ExecStart=/usr/local/sbin/supermicro fan auto
Nice=-10

supermicro-fan-auto.timer

[Unit]
Description=Supermicro Auto Fan Mode (Timer)

[Timer]
OnBootSec=60
OnUnitInactiveSec=45

[Install]
WantedBy=basic.target

supermicro-fan.service

[Unit]
Description=Supermicro Fan Control
Requires=openipmi.service
After=openipmi.service

[Service]
Type=oneshot
RemainAfterExit=true
StandardOutput=journal
ExecStart=/usr/local/sbin/supermicro fan full 50 50
ExecStop=/usr/local/sbin/supermicro fan default
Nice=-10

[Install]
WantedBy=multi-user.target

supermicro.cfg

# It's possible to include remote host arguments for ipmitool here.
# Create SDR cache file: ipmitool sdr dump /var/cache/ipmi/sdr/local
IPMITOOL_ARGS=( -S "/var/cache/ipmi/sdr/local" )

# Default fan mode.
# FANSPEED IGNORED!
DEFAULT_FANMODE="pue2"

# FULL: Default fan speed(s).
# One value per cooling zone.
# Values in percent as integer.
DEFAULT_FANSPEED=( 100 100 )

# FULL: Workaround for race condition.
# Otherwise it ignores new speed value(s).
# Use a value between 1 to 5 seconds.
DEFAULT_FANSLEEP=1

# Rules for auto fan adjustment.
# Use "0" for no change at a zone.
# <SENSOR> <TEMP> <ZONESPEED> ...
AUTOFAN_MIN=( "cpu 40   1   1"  "system 40    0   1"  "peripheral 40   0   1"  "dimm 50   0   1" )
AUTOFAN_MAX=( "cpu 80 100  50"  "system 60    0 100"  "peripheral 60   0 100"  "dimm 70   0 100" )

## Time-based multiplicator in percent.
## 100 is the original calculated speed.
## Day of week: 0-7; Start/end time: HHMM
## <DOW> <START> <END> <PERCENT> <BREAK>
#AUTOFAN_PENALTY=( "* 2200 0600 50 !" )

## Optional: Base speed for all cooling zones at auto fan mode.
## Only used if temperatures are lower than all triggers.
## This could lead to freaky up/down spinning of fans!
#AUTOFAN_BASE=( 1 1 )

## Custom temperature sources.
## Calls: smCustomSource<NAME>
#AUTOFAN_SOURCES=( "ssd" "hdd" )
#
#function smCustomSourceSSD
#{
#	hddtemp -n SAT:/dev/sd{a..d} | sort -n | tail -n 1 || echo 0
#}
#
#function smCustomSourceHDD
#{
#	curl --fail --silent --max-time 3 \
#		--header "Content-Type: application/json" \
#		--header "Authorization: Bearer 1337-EXAMPLE" \
#		--data '{"names": ["ada0", "ada1", "ada2", "ada3", "ada4", "ada5", "ada6", "ada7"], "powermode": "STANDBY"}' \
#		"https://truenas.example.net/api/v2.0/disk/temperatures" \
#	| jq -r '[ .[] ] | max | tonumber' 2>/dev/null \
#	|| \
#	(
#		stderr "Failed to fetch HDD temperature via TrueNAS API!"
#		echo 0
#	)
#}