Disk Usage

I wrote this VBScript to call on a scheduled task from servers to dump the local disk drive space to a CSV file so that over time I can see the decline (or incline if something magical is happening) of free disk space to estimate when a server is going to run out, roughly!

A few things to note; swap Win32_LogicalDisk for Win32_DiskDrive if you are NOT using a hardware RAID. This script runs on Windows Server 2003 servers all running on hardware RAIDs so the storage provided to the OS is over a virtual disk volume on top of a logical disk, not a physical disk!

Also, change 'arrProperty.FreeSpace' for 'arrProperty.Size' if you just want to see disk sizes.

' Script to monitor diskusage
' Written by James Bensley (jwbensley (at) gmail.com)
' ----------------------------------------------------------------------------------------

' ----------------------------------------DECLARATIONS------------------------------------
' Make sure we don't miss any variables out
Option Explicit

' Objects
Dim objWMIService ' An object to store our Windows Managment object reference
Dim objResults ' A collection of objects returned from our management query
Dim arrProperty ' An array of properties for each returned object
Dim objFSO ' Create an object for calling file system object for our output log
Set objFSO = CreateObject("Scripting.FileSystemObject")
Dim objLogFile

' Integers
Dim intArgCount ' How many args are we expecting
intArgCount = 3
Dim intL ' General integer for loop counting

' Strings
Dim strDriveLetter, strLogFile, strComputer, strLogOutput

Dim intReadMode

' ----------------------------------------------------------------------------------------

' -----------------------------------------MAIN LOOP--------------------------------------


' Check the parsed arguments
Argumentative()

' If the code returns here everything is good, lets being...
set objWMIService = GetObject("winmgmts:\\" & strComputer & "\root\cimv2")
set objResults = objWMIService.ExecQuery ("Select * From Win32_LogicalDisk") ' Query the logical disks
' We could have used Win32_DiskDrive but these are in a hardware RAID which has different properties

strLogOutput = Now() & vbNewLine ' Start the ouput log with the current date and time

For Each arrProperty in objResults
       If arrProperty.DriveType = 3 Then
               If strDriveLetter = "*" Then
                       strLogOutput = strLogOutput & "," & arrProperty.Name
                       strLogOutput = strLogOutput & "," & FormatNumber((arrProperty.FreeSpace / 1024^3), 2) & "GB" & vbNewLine
               Else
                       If arrProperty.Name = strDriveLetter then
                               strLogOutput = strLogOutput & "," & arrProperty.Name
                               strLogOutput = strLogOutput & "," & FormatNumber((arrProperty.FreeSpace / 1024^3), 2) & "GB" & vbNewLine
                       End If
               End If
       End If
Next

' Are we priting this to the screen or to a CSV?
If strLogFile = "*" Then

       Wscript.echo strLogOutput

Else

       ' Check weather are log file exists, i.e. it has been ran today
       If Not objFSO.FileExists(strLogFile) Then
               objFSO.CreateTextFile(strLogFile) ' If not then create it
               ' and set the read mode
               intReadMode = 2 ' 2 is for writing
               strLogOutPut = "Date,Drive,Free Space" & vbNewLine & strLogOutput
       Else
               intReadMode = 8 ' 8 is for appending
       End If

       Set objLogFile = objFSO.OpenTextFile (strLogFile, intReadMode, True)
       objLogFile.Write(strLogOutPut)
       objLogFile.Close

End IF

' Clean up after your self kids
set objWMIService = Nothing
set objResults = Nothing

' ----------------------------------------------------------------------------------------

' -----------------------------------------SUBROUTINES------------------------------------

Sub Argumentative()
' This sub handles the parsed arguments to the script to make sure everything is honky-dory

       ' Make sure we haven't been given too many arguments otherwise
       ' the script is going to do what the user expected
       If WScript.Arguments.Count > intArgCount Then
               WScript.Echo "Error: to many arguments were given"
               Call PrintUsage() ' Remind the user of the usage details
               WScript.Quit ' Lets exit this town!
       End If

       ' What if not enough arguments were given?
       If WScript.Arguments.Count < intArgCount Then
               WScript.Echo "Error: not enough arguments were given"
               Call PrintUsage() ' Remind the use of the usage details
               WScript.Quit ' Lets exit this town!
       End IF

       On Error Resume Next

       strComputer = WScript.Arguments.item(0)
       strDriveLetter = WScript.Arguments.item(1)
       strLogFile = WScript.Arguments.item(2)


       ' Did an error occur getting the arguments?
       If Err.Number <> 0 Then
               WScript.Echo "Error: failed to set parsed arguments"
               WScript.Echo "Error Number: " & Err.Number
               WScript.Echo "Error Number (Hex): " & Hex(Err.Number)
               WScript.Echo "Source: " &  Err.Source
               WScript.Echo "Description: " &  Err.Description
               Call PrintUsage() ' Remind the use of the usage details
               WScript.Quit ' Lets exit this town!
       End If

End Sub


sub PrintUsage()
' This sub prints the usage info

       ' Print out the arguments parsed for aditional debugging help
       Wscript.Echo vbNewLine & "Arguments given:"
       For intL = 0 to WScript.Arguments.Count - 1
               Wscript.Echo WScript.Arguments.Item(intL)
       Next

       WScript.Echo vbNewLine & "Useage details:"
       WScript.Echo "<ScriptName>.vbs <Computer> <Drive Letter or *> <* (print to screen) or path_to_log.csv>"
       WScript.Echo vbNewLine & "DiskStats.vbs . C: *"
       WScript.Echo vbNewLine & "OR" & vbNewLine & vbNewLine & "DiskStats.vbs 2k3FS01 * C:\LogsDir\FS01_All_Drives.csv" & vbNewLine

End Sub

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