PowerShell run script simultaneously - powershell

Question

I created a PowerShell script to remove all files and folders older than X days. This works perfectly fine and the logging is also ok. Because PowerShell is a bit slow, it can take some time to delete these files and folders when big quantities are to be treated.
My questions: How can I have this script ran on multiple directories ($Target) at the same time?
Ideally, we would like to have this in a scheduled task on Win 2008 R2 server and have an input file (txt, csv) to paste some new target locations in.
Thank you for your help/advise.
The script
#================= VARIABLES ==================================================
$Target = \\share\dir1"
$OlderThanDays = "10"
$Logfile = "$Target\Auto_Clean.log"
#================= BODY =======================================================
# Set start time
$StartTime = (Get-Date).ToShortDateString()+", "+(Get-Date).ToLongTimeString()
Write-Output "`nDeleting folders that are older than $OlderThanDays days:`n" | Tee-Object $LogFile -Append
Get-ChildItem -Directory -Path $Target |
Where-Object { $_.LastWriteTime -lt (Get-Date).AddDays(-$OlderThanDays) } | ForEach {
$Folder = $_.FullName
Remove-Item $Folder -Recurse -Force -ErrorAction SilentlyContinue
$Timestamp = (Get-Date).ToShortDateString()+" | "+(Get-Date).ToLongTimeString()
# If folder can't be removed
if (Test-Path $Folder)
{ "$Timestamp | FAILLED: $Folder (IN USE)" }
else
{ "$Timestamp | REMOVED: $Folder" }
} | Tee-Object $LogFile -Append # Output folder names to console & logfile at the same time
# Set end time & calculate runtime
$EndTime = (Get-Date).ToShortDateString()+", "+(Get-Date).ToLongTimeString()
$TimeTaken = New-TimeSpan -Start $StartTime -End $EndTime
# Write footer to log
Write-Output ($Footer = #"
Start Time : $StartTime
End Time : $EndTime
Total runtime : $TimeTaken
$("-"*79)
"#)
# Create logfile
Out-File -FilePath $LogFile -Append -InputObject $Footer
# Clean up variables at end of script
$Target=$StartTime=$EndTime=$OlderThanDays = $null

Answer 1

One way to achieve this would be to write an "outer" script that passes the directory-to-be-cleaned, into the "inner" script, as a parameter.
For your "outer" script, have something like this:
$DirectoryList = Get-Content -Path $PSScriptRoot\DirList;
foreach ($Directory in $DirectoryList) {
Start-Process -FilePath powershell.exe -ArgumentList ('"{0}\InnerScript.ps1" -Path "{1}"' -f $PSScriptRoot, $Directory);
}
Note: Using Start-Process kicks off a new process that is, by default, asynchronous. If you use the -Wait parameter, then the process will run synchronously. Since you want things to run more quickly and asynchronously, omitting the -Wait parameter should achieve the desired results.
Invoke-Command
Alternatively, you could use Invoke-Command to kick off a PowerShell script, using the parameters: -File, -ArgumentList, -ThrottleLimit, and -AsJob. The Invoke-Command command relies on PowerShell Remoting, so that must enabled, at least on the local machine.
Add a parameter block to the top of your "inner" script (the one you posted above), like so:
param (
[Parameter(Mandatory = $true)]
[string] $Path
)
That way, your "outer" script can pass in the directory path, using the -Path parameter for the "inner" script.