Friday, 14 October 2016

Windows Server Health Check Script - Powershell

Here is a script that I have developed to run a "health check" on a windows server. The script can be run on demand, but I tend to run them from Windows Task Scheduler with a trigger to run on windows startup to automatically check some of the key things within a windows server. At a high level, here is what is contained within the script;
  • A report of all services with a start mode of "Automatic" but are not in a "running" state
  • Any events in the windows Application log from the past 24 hours that are not categorized as "informational"
  • Any events in the windows System log from the past 24 hours that are not categorized as "informational"
  • A size report of all logical disks in the server showing size, and free space in GB and as a percentage
  • Average CPU load on server
  • Current memory usage (as a percentage)
All this information is retrieved by the script and stored in a .html file. At the end of the script the .html file is saved to disk and sent as an email attachment.

A few other points to note;
  • The start-sleep command is used at the start of the script to delay the script running for 300 seconds (5 minutes). If the script runs as soon as it is triggered on windows startup, not all windows components are ready/loaded and the results of the script are incomplete
  • The log file is saved by default into C:\Admin\ServerHealthChecks with a filename based on the target IP/hostname and date/time the script runs. This can be changed using the $logfile variable. Make sure the path specified in $logfile exists otherwise the .html file will not save correctly
  • If a disk has 10-20% free space, it's text will be orange in colour. Less than 10% will be red. Otherwise it will be green
  • Likewise, if CPU usage is 80-90% it will be orange. 90-100% will be red
  • If free memory is 10-20%, it will be orange. Less than 10% will be red
  • Be sure to update the variables at the end of the script (under #Send Log File via Email) to work with your email system/environment
Powershell script/code is below;

#Server Health Checker
#Author: Peter Morrissey

start-sleep 300

$target = ""

#Get Last Bootup Time
$osprops = get-wmiobject -class win32_operatingsystem 
$lastboot = $osprops.ConvertToDateTime($osprops.LastBootUpTime)

#Log File
$fulldate = Get-Date
$logfile = "c:\" + "Admin\" + "ServerHealthChecks\" + $FullDate.ToString("yyyyMMddHHmm") + "-" + "$Target" + ".html"
$global:strname = $env:username
$global:html = @()
$html += "<html>"
$html += '<font face="courier">'
$html += "<title>Server Health Check - $Target</title>"
$html += "<h3>$FullDate</h3>"
$html += "<h4>Server Health Check Script - Run by $global:strname</h4>"
$html += "<h4>Target Server: $Target</h4>"
$html += "<h4>Hostname: $env:computername</h4>"
$html += "<h4>Last Boot: $lastboot </h4>"
$html += "<p>"
$html += "******************************************************************************************* <p>"

#Services Check
write-host "Getting Service Information"
$html += '<u>Service Report - Services with StartMode "Auto" and State not currently "Running" </u><p>'

$servicelist = invoke-command -computername $target {
        get-wmiobject -class Win32_Service | Where {$_.StartMode -eq "Auto" -and $_.State -ne "Running"} | Select DisplayName, Name, StartMode, State
if ($servicelist){$temphtml = $servicelist | Select DisplayName, Name, StartMode, State | ConvertTo-HTML -fragment
                    ForEach ($line in $temphtml){$html += "$Line"} }
ELSE {write-host "All automatic services are running";$html += "All automatic services are running <p>"}

$html += "<p> ******************************************************************************************* <p>"

#EventLog Checks
write-host "Querying Application Log on $Target"
$appeventlog = invoke-command -computername $target {
        $targetDate = Get-Date
        $targetdate = $targetdate.adddays(-1)
        get-eventlog -logname "Application" -after $targetdate | where-object {$_.entrytype -ne "Information" -and $_.Source -ne "Print" -and $_.Source -ne "TermServDevices"} 

if ($appeventlog){#write-host $AppEventLog
                  $html += "<u>Application Log Non-Information Events (Last 24 Hours)</u><p>" 
                  $temphtml = $appeventlog |  Select TimeGenerated, EntryType, Source, Message | ConvertTo-HTML -fragment
                  foreach ($line in $temphtml){$html += "$line"}
ELSE {$html += "No non-informational events found in application log in past 24 hours <p>"}

$html += "<p>*******************************************************************************************<p>"

write-host "Querying System Log on $Target"

$syseventlog = invoke-command -computername $Target {
        $targetdate = get-date
        $targetdate = $targetdate.adddays(-1)
        get-eventlog -logname "System" -after $targetdate | where-object {$_.entrytype -ne "Information" -and $_.source -ne "Print" -and $_.source -ne "TermServDevices"} 

if ($syseventlog){#write-host $syseventlog
                  $html += "<u>System Log Non-Information Events (Last 24 Hours)</u><p>"
                  $temphtml = $syseventlog | Select TimeGenerated, EntryType, Source, Message | ConvertTo-HTML -fragment
                  ForEach ($line in $temphtml){$html += "$Line"}
else {$html += "No non-informational events found in system log in past 24 hours<p>"}

$html += "<p>*******************************************************************************************<p>"

#Local Disk Health Check
write-host "Getting logical disk information"
$diskreport = invoke-command -computername $target {
    Get-WmiObject Win32_logicaldisk | Select DeviceID, MediaType, VolumeName, `
    @{Name="Size(GB)";Expression={[decimal]("{0:N0}" -f($_.size/1gb))}}, `
    @{Name="Free Space(GB)";Expression={[decimal]("{0:N0}" -f($_.freespace/1gb))}}, `
    @{Name="Free (%)";Expression={"{0,6:P0}" -f(($_.freespace/1gb) / ($_.size/1gb))}} `

$html += "<u>Logical Disk Report</u><p>"
$temphtml = $DiskReport | Select DeviceID, VolumeName, "Size(GB)", "Free Space(GB)", "Free (%)" | ConvertTo-HTML -fragment
foreach ($Line in $temphtml)
    if ($line -like "*%<*")
        $lineindex = [array]::IndexOf($temphtml, $line)
        $templine = $line -split "%"
        $templine = $templine -replace(" ","")
        $templine = $templine[0] -split "<td>"
        $templine = $templine[5]
        $templine = $templine.trim()
        $templine = [decimal]$templine
        if ($templine -le 20 -and $templine -ge 10){$temphtml[$lineindex] = $temphtml[$lineindex].Replace("<td>",'<td><font color="orange">')}
        if ($templine -lt 10 ){$temphtml[$lineindex] = $temphtml[$lineindex].Replace("<td>",'<td><font color="red">');
                                $smtpclient = new-object 
                                $mailmessage = New-Object 
                                $smtpclient.Host = "" 
                                $mailmessage.from = ("") 
                                $mailmessage.Subject = “Server Health Check Alert - Disk Space Low - $target"
                                $mailmessage.Body = "Low disk space found on $target -  $temphtml"
                                $mailmessage.IsBodyHtml = $true

foreach ($line in $temphtml){$html += "$line"}

$html += "<p>*******************************************************************************************<p>"

#Check CPU Load
write-host "Getting CPU Stats"
$cpudata = get-wmiobject win32_processor -computername $target | measure-object -property LoadPercentage -average | select Average
$html += "<u>CPU Load (Average)</u><p>"
$cpuusage = $($cpudata.average)
    if ($cpuusage -ge 80 -and $cpuusage -le 90){$html += '<font color="orange">' + "Average CPU Load: $cpuusage%" + '</font>'}
    elseif ($cpuusage -gt 90){$html += '<font color="red">' + "Average CPU Load: $cpuusage%" + '</font>'}
    elseif ($cpuusage -lt 80){$html += '<font color = "green">' + "Average CPU Load: $cpuusage%" + '</font>'}
$html += "<p>*******************************************************************************************<p>"

#Check Memory Usage
write-host "Getting Memory Usage"
$html += "<u>Memory Usage Report</u><p>"
$memdata = get-wmiobject win32_operatingsystem -computername $target | select FreePhysicalMemory, FreeVirtualMemory, TotalVirtualMemorySize, TotalVisibleMemorySize
$freephysicalmem = $($memdata.freephysicalmemory)
$freevirtualmem = $($memdata.freevirtualmemory)
$totalvirtualmem = $($memdata.totalvirtualmemorysize)
$totalvisiblemem = $($memdata.totalvisiblememorysize)
$memusage = ($totalvisiblemem - $freephysicalmem) / $totalvisiblemem * 100
$freemem = $freephysicalmem / $totalvisiblemem * 100
[decimal]$freemem = "{0:N0}" -f $freemem

if ($freemem -lt 10){$html += '<font color="red">' + "Free Memory (%): $freemem" + '</font>'}
elseif ($freemem -gt 10 -and $freemem -le 20){$html += '<font color="orange">' + "Free Memory (%): $freemem" + '</font>'}
elseif ($freemem -gt 20){$html += '<font color="green">' + "Free Memory (%): $freemem" + '</font>'}
$html += "<p>*******************************************************************************************<p>"

#Export Log File
$html | out-file $LogFile

#Open Log File in Internet Explorer
#Invoke-Item $Logfile

#Send Log File via Email
$smtpclient = new-object 
$mailmessage = New-Object 
$smtpclient.Host = "" 
$mailmessage.from = ("") 
$mailmessage.Subject = “Server Health Check Results - $target"
$mailmessage.Body = "Server Health Check Results for $target"
$mailmessage.IsBodyHtml = $true


  1. Hi Peter,

    Can we run this script on multiple servers, by assigning input file to a variable?


  2. Hi Peter,
    I am getting error :Exception calling "Send" with "1" argument(s): "Failure sending mail."
    At C:\serverhealth.ps1:165 char:1
    + $smtpclient.Send($mailmessage)
    + ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo : NotSpecified: (:) [], MethodInvocationException
    + FullyQualifiedErrorId : SmtpException