{"id":1750,"date":"2011-11-11T11:04:07","date_gmt":"2011-11-11T16:04:07","guid":{"rendered":"http:\/\/jdhitsolutions.com\/blog\/?p=1750"},"modified":"2011-11-11T11:04:07","modified_gmt":"2011-11-11T16:04:07","slug":"friday-fun-perf-counters-with-write-progress","status":"publish","type":"post","link":"https:\/\/jdhitsolutions.com\/blog\/powershell\/1750\/friday-fun-perf-counters-with-write-progress\/","title":{"rendered":"Friday Fun Perf Counters with Write-Progress"},"content":{"rendered":"

While working on my course for TrainSignal on managing Windows Servers with PowerShell<\/a>, I came up with an interesting use of the Write-Progress cmdlet. I was working on the performance monitoring lesson and realized I could use Write-Progress as rudimentary graphing tool. The cmdlet has a parameter that lets you specify a value that shows up as the progress bar. Normally we think about moving from 0 to 100, but you can specify any value. So I thought why not pass a performance counter value? After a little work I came up with this demo script. <\/p>\n

The script uses Get-WMIObject to retrieve a performance counter property. My demo needs a property with a value between 1 and 100 because I am using the -PercentComplete parameter with Write-Progress. You could use other types of values but you would need to scale it. You also need to only get a single instance. In my demo I'm querying the Win32_PerfFormattedData_PerfDisk_LogicalDisk class, filtering on drive C: The property I'm checking is PercentDiskTime. I use a simple Get-WMIObject expression to retrieve the value.<\/p>\n

[cc lang=\"PowerShell\"]
\n$stat=get-wmiobject -class $activity -filter $filter -computername $computername -ErrorAction Stop
\n[\/cc]<\/p>\n

Then it is simply a matter of using Write-Progress to display it.<\/p>\n

[cc lang=\"PowerShell\"]
\nWrite-progress -Activity $activity -status $status -currentoperation $current -PercentComplete $stat.$Property
\n[\/cc]<\/p>\n

The script loops for as many times as you want. I have a default of 60. You can also specify the interval between samplings. My demo default is 1 second. Here's what the complete script looks like.<\/p>\n

[cc lang=\"PowerShell\"]
\n<#\n .Synopsis\n Demo WMI Perf Counter Graph\n .Description\n This demonstration script uses the Write-Progress cmdlet to display\n the value of a WMI Performance counter. Ideally, the counter will \n have a value of between 1 and 100. Otherwise you might need to \n scale the value.\n \n You must specify a WMI Performance counter. The demo sample is:\n \n Win32_PerfFormattedData_PerfDisk_LogicalDisk\n \n and a filter to limit it to a single instance. The demo filter is:\n \n Name='C:'\n \n Finally, select a property. The demo property is PercentDiskTime. \n The demo will check every 1 second (the -Sleep parameter) up to \n 60 times (the -Maximum parameter).\n \n You can also specify the name of a CSV log file to hold the results.\n \n #><\/p>\n

[cmdletbinding()]<\/p>\n

Param(
\n[Parameter(Position=0)]
\n[ValidateNotNullorEmpty()]
\n[string]$Class=\"Win32_PerfFormattedData_PerfDisk_LogicalDisk\",
\n[Parameter(Position=1)]
\n[ValidateNotNullorEmpty()]
\n[string]$Filter=\"Name='C:'\",
\n[Parameter(Position=2)]
\n[ValidateNotNullorEmpty()]
\n[string]$Property=\"PercentDiskTime\",
\n[string]$Computername=$env:computername,
\n[int]$Sleep=1,
\n[int]$Maximum=60,
\n[string]$Log
\n)<\/p>\n

Write-Verbose (\"Querying {0} filter {1} on {2} every {3} second(s) {4} times.\" -f $class,$filter,$computername,$sleep,$maximum)<\/p>\n

#values for Write-Progress
\n$activity=$class
\n$status=\"$Property -> $Filter\"
\n$current=$computername.ToUpper()<\/p>\n

Write-Verbose \"Graphing the $Property property\"<\/p>\n

#define an array to hold the results
\n$results=@()
\nfor ($i=1; $i -le $maximum; $i++) {
\n Try {
\n $stat=get-wmiobject -class $activity -filter $filter -computername $computername -ErrorAction Stop
\n $results+=$stat
\n Write-progress -Activity $activity -status $status -currentoperation $current -PercentComplete $stat.$Property
\n sleep -seconds $sleep
\n }
\n Catch {
\n Write-Warning $_.Exception.Message
\n Return
\n }
\n}<\/p>\n

if ($Log) {
\n #export results to a file
\n Write-Verbose \"Exporting results to $log\"
\n $results | export-csv -Path $log
\n}<\/p>\n

Write-Progress -Activity $activity -status \"Finished\" -Completed
\nWrite-Verbose \"Finished\"
\n[\/cc]<\/p>\n

Because you might want to save results as well I added a parameter so you could specify a file name. The performance data will be exported to a CSV file. Here's a brief video of the script in action.<\/p>\n