Powershell - Where-Object in forEach Loop - powershell

Question

I need some help for executing a little script and filtering results ...
I checkmy VM diskspace with the following script
Get-VM | ForEach-Object {
$VM = $_
$_.Guest.Disks | ForEach-Object {
$Report = "" | Select-Object -Property VM,Path,Capacity,FreeSpace,PercentageFreeSpace
$Report.VM = $VM.Name
$Report.Path = $_.Path
$Report.Capacity = $_.Capacity
$Report.FreeSpace = $_.FreeSpace
if ($_.Capacity) {$Report.PercentageFreeSpace = [math]::Round(100*($_.FreeSpace/$_.Capacity))}
$report
}
}
But I'd like to add a filter that my report only show me PercentageFreeSPace lesser than 20.
I try to add a where-object condition to my report with no success...
Can somebody help me please ? I m a beginner in PS...
Thanks in advance,
Best regards

Answer 1

For future questions you should format your script to be more readable.
I believe I have done it quite well below:
[EDIT] Seems that something gone wrong with displaying your question on my laptop. Just after my answer, the formatting is almost the same as provided below.
Get-VM | ForEach-Object {
$VM = $_
$_.Guest.Disks | ForEach-Object {
$Report = "" | Select-Object -Property VM,Path,Capacity,FreeSpace,PercentageFreeSpace $report
$Report.VM = $VM.Name
$Report.Path = $_.Path
$Report.Capacity = $_.Capacity
$Report.FreeSpace = $_.FreeSpace
if ($_.Capacity) {
$Report.PercentageFreeSpace = [math]::Round(100*($_.FreeSpace/$_.Capacity))
}
$report
}
}
To be honest I do not understand why you are using pipe at line 4.
Regarding your question, you should puy Where-Object clause before you will go to second for each loop.

Answer 2

First off, try and avoid multiple nested pipes to foreach-object, use foreach instead. That is, don't do
Get-VM | ForEach-Object {
$VM = $_
$_.Guest.Disks | ForEach-Object {
but
foreach($vm in Get-VM) {
foreach($disk in $vm.Guest.disks) {
This makes it easy to see what objects are handled later, and there isn't need to save current object on the pipeline into a temp variable (which you do by $VM = $_).
Also, objects can be initialized via a hash table instead of using select-object. Like so,
$pctLimit = 20 # Variable sets percentage limit instead of a magic number
foreach($vm in Get-VM) {
foreach($disk in $vm.Guest.Disks) {
# Report object is created via hash table
$Report = new-object PSObject -Property #{
VM = $VM.Name
Path = $disk.Path
Capacity = $disk.Capacity
FreeSpace = $disk.FreeSpace
ZeroDisk = ($disk.Capacity -gt 0) # NB: calculated property
}
if (-not $Report.ZeroDisk) { # Process only non-zero disks
$Report.PercentageFreeSpace = [math]::Round(100*($Report.FreeSpace/$Report.Capacity))
if($Report.PercentageFreeSpace -lt $pctLimit) {
$report
} else {
# Disk had more than $pctLimit free space. Now what?
}
} else {
# Disk had zero capacity. Now what?
}
}
}

Answer 3

FIrst of all thanks for your help
I manage to filter with the following
Get-VM | ForEach-Object {
$VM = $_
$_.Guest.Disks | ForEach-Object {
$Report = "" | Select-Object -Property VM,Path,Capacity,FreeSpace,PercentageFreeSpace
$Report.VM = $VM.Name
$Report.Path = $_.Path
$Report.Capacity = $_.Capacity
$Report.FreeSpace = $_.FreeSpace
if ($_.Capacity) {$Report.PercentageFreeSpace = [math]::Round(100*($_.FreeSpace/$_.Capacity))}
if( $_.Capacity -and $Report.PercentageFreeSpace -lt 30 ) {
$Report
}
}
}
`
Thanks,
Best regards