Script to automatically set fan speed during parity check for Dell R720XD

I just wanted to share this since it's helped me and I thought others might find it useful. This script checks for when parity check is running and automatically sets the fan speed to 60% then automatically reverts back to automatic control when parity check ends. You can set the speed to whatever you want I just find 60% works well for my specific circumstances. 

This was made with chatgpt so please excuse if there is a better way of doing this, I'd appreciate any feedback if it could be improved.

#!/bin/bash

# Configuration
IPMI_USER="enter username"             # IPMI username
IPMI_PASS='enter password'             # IPMI password
IPMI_IP="enter ip of server"           # IPMI IP address
FAN_SPEED=60                           # Desired fan speed percentage (60%), only used to display fan speed %
CHECK_INTERVAL=60                      # Time (in seconds) between checks
LOG_FILE="/mnt/user/appdata/scripts/fan_control.log"

# Commands to enable manual fan control, set fan speed, and revert to automatic
ENABLE_MANUAL_FAN_CMD="ipmitool -I lanplus -H $IPMI_IP -U $IPMI_USER -P $IPMI_PASS raw 0x30 0x30 0x01 0x00"
SET_FAN_SPEED_CMD="ipmitool -I lanplus -H $IPMI_IP -U $IPMI_USER -P $IPMI_PASS raw 0x30 0x30 0x02 0xff 0x3C"
SET_AUTO_FAN_CMD="ipmitool -I lanplus -H $IPMI_IP -U $IPMI_USER -P $IPMI_PASS raw 0x30 0x30 0x01 0x01"

# Function to log events with a timestamp
log_event() {
    echo "$(date '+%Y-%m-%d %H:%M:%S') - $1" >> $LOG_FILE
}

# Function to check if a parity check is running based on mdResync
is_parity_check_running() {
    mdResync=$(mdcmd status | grep -oP 'mdResync=\K[0-9]+')
    if [[ "$mdResync" -gt 0 ]]; then
        return 0  # Parity check is running
    else
        return 1  # Parity check is not running
    fi
}

# Main script loop
log_event "Starting IPMI Fan Control Script for Parity Check..."
FAN_SPEED_SET=false
MANUAL_CONTROL_ENABLED=false

while true; do
    if is_parity_check_running; then
        # If a parity check is running
        if [ "$FAN_SPEED_SET" = false ]; then
            # Enable manual fan control only once when parity check starts
            if [ "$MANUAL_CONTROL_ENABLED" = false ]; then
                log_event "Enabling manual fan control..."
                eval $ENABLE_MANUAL_FAN_CMD
                MANUAL_CONTROL_ENABLED=true
            fi

            # Set fan speed to 60% once when parity check starts
            log_event "Parity check detected. Setting fan speed to ${FAN_SPEED}%. "
            eval $SET_FAN_SPEED_CMD
            FAN_SPEED_SET=true
        fi
    else
        # If no parity check is running
        if [ "$FAN_SPEED_SET" = true ]; then
            # Revert to automatic fan control after parity check completes
            log_event "Parity check completed. Reverting fan control to automatic."
            eval $SET_AUTO_FAN_CMD
            FAN_SPEED_SET=false
            MANUAL_CONTROL_ENABLED=false
        fi
    fi
    sleep $CHECK_INTERVAL
done

Edited March 31, 20251 yr by Android_18