DiskMon - Monitor your free space

This is an old driver based LedBorg script
We recommend using the new driver free based scripts for LedBorg.
The new driver free examples can be found here, the installation can be found here.

We like being able to glance at things and immediately know if they are happy without relying on manually checking.
So when our file server started running out of space we thought it would have been great to be warned.


We decided to use an LedBorg to show how full a given mount point (usually a drive or network share),
the colour displayed would be the following:

<=11%

<=22%

<=33%

<=44%

<56%

<67%

<78%

<89%

>=89%

and if a mount was unavailable it would warn us by flashing red!

The result was DiskMon.py, a Python script which reads how full a mount point is and controls an LedBorg appropriately.

Here's the code, you can download the DiskMon script file as text here
Save the text file on your pi as DiskMon.py
Make the script executable using
chmod +x DiskMon.py
and run using
sudo ./DiskMon.py
to monitor the default mount ('/', the SD card itself), or
sudo ./DiskMon.py mymount
to monitor another mount (e.g. /boot)

#!/usr/bin/env python
# coding: Latin-1

# Load library functions we want
import sys
import os
import time
import re

# Parameters to the script
defaultMount = '/'                          # Mount path to observe when none is provided
errorColour = '200'                         # Colour to flash when the mount is not found
interval = 1.0                              # Delay in seconds between refreshes

# Colours from most free to most full
driveColour = ['002', '012', '022', '021', '020', '120', '220', '210', '200']

# Function to write the LedBorg colour
def SetLedColour(colour):
    LedBorg = open('/dev/ledborg', 'w')     # Open the LedBorg device for writing to
    LedBorg.write(colour)                   # Write the colour string to the LedBorg device
    LedBorg.close()                         # Close the LedBorg device

# Get user input
if len(sys.argv) > 1:
    mountPath = sys.argv[1]
else:
    mountPath = defaultMount
print 'Monitoring "' + mountPath + '"'

# Set our starting state
errorOn = True

# Loop indefinitely
while True:
    # Query the disk free program (df) for drive statistics
    rawDataFile = os.popen('df 2> /dev/null')   # The '2> /dev/null' is used to suppress any errors
    rawData = rawDataFile.readlines()
    rawDataFile.close()
    # Parse data looking for our mount
    used = -1.0
    for line in rawData:
        # Split the raw text into usable chunks
        line = line[:-1]                            # Remove last character (newline symbol)
        line = re.sub('  *', ' ', line)             # Replace all instances of multiple spaces with a single space
        token = line.split(' ')                     # Split into many strings at the space characters
        # See if we have the right line
        if token[5] == mountPath:
            used = float(token[4][:-1])                 # Take the Use%, strip the '%' symbol and convert to a number
            break                                       # End the search early
    # Pick our colour and set it
    if used < 0.0:
        errorOn = not errorOn                       # Toggle if the error flash is on or off
        # Set error flash
        if errorOn:
            SetLedColour(errorColour)                   # Set to error colour
        else:
            SetLedColour('000')                         # Set to off
    else:
        used /= 100.0                               # Make used between 0 and 1
        used *= len(driveColour)                    # Increase to cover the colour list
        used =  int(used)                           # Trim to the next integer down
        if used >= len(driveColour):
            used = len(driveColour) - 1                 # If we had 100% or larger cap at the highest colour
        SetLedColour(driveColour[used])             # Set the appropriate colour
    # Wait for the interval
    time.sleep(interval)