PowerShell run script simultaneously

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.

• DarkLite1: Thank you Trevor. I was also looking at Start-Job, which seems a bit similar. Is there also a way to limit it to only 3 or 4 directories being processed at the same time? Otherwise it might kill the server..
• user189198: Check out the Invoke-Command command. It has the -AsJob and -ThrottleLimit parameters. These should help you control script execution. Keep in mind that Invoke-Command relies on PowerShell Remoting, so that has to be enabled at least locally.
• user189198: Oops - disregard. The -ThrottleLimit parameter only throttles the systems that a script is being remotely deployed to. It doesn't throttle the objects that are being inputted to it.
• DarkLite1: Maybe it's even better with regards to load balancing to have the script run remotely with Enter-PSSession and use variables for server name and local path. But then I have to rewrite it completely and I need to know if PowerShell is a requirement to run this remotely.
• DarkLite1: Yes Trevor, on remote with Invoke-Command it runs only 22 seconds instead of 30 minutes for over 10.000 files. Big win there I would say :) Thanks again for your help.