Property is empty when run through Invoke-Command - powershell

I am trying to individually monitor memory usage of a process (w3wp.exe) that has multiple instances of itself by filtering out a string found in the process' CommandLine property.
It works when I run this script locally:
$proc = (WmiObject Win32_Process -Filter "Name = 'w3wp.exe'" | Where-Object {$_.CommandLine -like "*SomeTextFromCl*"})
$id = $proc.ProcessId
$ws = [math]::round((Get-Process -Id $id).WS/1MB)
Write-Host $ws
However, when I try to run it remotely through Invoke-Command, I get an error telling that the Id property's value is null:
Cannot bind argument to parameter 'Id' because it is null.
+ CategoryInfo : InvalidData: (:) [Get-Process], ParameterBindingValidationException
+ FullyQualifiedErrorId : ParameterArgumentValidationErrorNullNotAllowed,Microsoft.PowerShell.Commands.GetProcessCommand
+ PSComputerName : RemoteServerName
My Invoke-Command syntax is:
Invoke-Command -ComputerName RemoteServerName -FilePath script.ps1 -Credential $mycredential
I'm sure it's simple but I'm back to PS after a long absence and I had a look around but couldn't find anything really helpful.

You are writing the answer to the console. You use the ps1 as a function, so you should use:
return $ws
instead of
write-host $ws

Related

cannot validate argument on parameter "Path" The argument is null or empty

I was trying to create a simple script that would go to a server and get the acl details of a folder. I tested the command:
Invoke-command -Computername Servername -ScriptBlock {(Get-Acl "\\Server\Folder\user folders").access | ft- auto}
This worked ok. However when I was trying to put it into a script that would allow me to enter the path in via a variable I always get:
Cannot validate argument on parameter 'Path'. The argument is null or empty. Supply an argument that is not null or empty and then
try the command again.
+ CategoryInfo : InvalidData: (:) [Get-Acl], ParameterBindingValidationException
+ FullyQualifiedErrorId : ParameterArgumentValidationError,Microsoft.PowerShell.Commands.GetAclCommand
Here is my script:
#get folder permissions from remote computer
$serverName = read-host "Please enter the name of the target server"
$folderPath = "\\server_name\Folder\user folders"
#read-host "Please enter the full path to the target folder"
Invoke-command -ComputerName $serverName -ScriptBlock {(get-acl $folderPath).access | ft -wrap}
Its probably something very simple, but I'd appreciate the help.
The issue is because you are trying to use the $folderPath variable, but on the remote computer that variable does not exist.
You will need to pass it through as an argument. There are multiple ways to do so, two such ways are below:
# Add desired variable to ArgumentList and define it as a parameter
Invoke-command -ComputerName $serverName -ArgumentList $folderPath -ScriptBlock {
param($folderPath)
(get-acl $folderPath).access | ft -wrap
}
OR
# In PS ver >= 3.0 we can use 'using'
Invoke-command -ComputerName $serverName $folderPath -ScriptBlock {(get-acl $using:folderPath).access | ft -wrap}

retrieve vhdx path from a remote server

hi i' m trying to retrieve the vhdx of specified vmname from the remote host server
here part of the script
$pth="C:\path\resize-vm"
$list=gc $pth\list-host.txt
foreach ($hostserver in $list) {
$vm=(Invoke-Command -ComputerName $hostserver -ScriptBlock {Get-VM}).VMName
Write-Host -NoNewline " here the vm installed in " $hostserver `r`n $vm
$vmname=Read-Host -Prompt "please chose a vmname to resize "
#the issue in the last line
$pathvhd=Invoke-Command -ComputerName $hostserver -ScriptBlock {(Get-VMHardDiskDrive -VMName $vmname).path}
When I launch this command $vmname="dc-kozhan"
I am getting this error
Cannot validate argument on parameter 'VMName'. The argument is null
or empty. Provide an argument that is not null or empty, and then try
the command again.
+ CategoryInfo : InvalidData: (:) [Get-VMHardDiskDrive], ParameterBindingValidationException
+ FullyQualifiedErrorId : ParameterArgumentValidationError,Microsoft.HyperV.PowerShell.Commands.GetVMHardDiskDrive
Command
+ PSComputerName : h-uludag-3
But when I specified dc-kozhan literally it work
PS C:\Users> Invoke-Command -ComputerName $hostserver -ScriptBlock {(Get-VMHardDiskDrive -VMName "DC-KOZAHAN")
.path}
V:\DC-KOZAHAN\DC-KOZAHAN-SYSTEM.vhdx
V:\DC-KOZAHAN\DC-KOZAHAN-DIRECTORY.vhdx
V:\DC-KOZAHAN\DC-KOZAHAN-SYSVOL.vhdx
V:\DC-KOZAHAN\DC-KOZAHAN-BACKUP.vhdx
does anyone have an idea why it does not work when it's specified in a variable
You need to understand how to pass arguments inside the scriptblock. The scope is different when you try to pass the value inside the scriptblock. As a result, $VMname is becoming null in your first statement.
Kindly change your existing Invoke-command statement to the below one:
Invoke-Command -ComputerName $hostserver -ScriptBlock {Param([string]$vmname)(Get-VMHardDiskDrive -VMName $vmname)} -ArgumentList $vmname
Also, my suggestion for you to read about the argumentlist in powershell in case invoke-command
Hope it helps.

PowerShell Positional parameter cannot be found that accepts argument 'Get-WindowsFeature'

Calling out for some PowerShell help again !!
I have the below which is trying to connect to a remote machine and return all the installed WindowsFeatures.. then I will try to export the list (but I have not been able to that far yet).
Invoke-Command -ComputerName VM01 -ScriptBlock { Get-Module ServerManager Get-WindowsFeature | Where-Object{$_.Installed -match "True" } | Select-Object -Property Name } -credential TestUser01
After running the above I am correctly presented with a login screen to allow me to enter a password then the following error appears, I don't believe I know enough about PowerShell and the use of Positional parameters;
A positional parameter cannot be found that accepts argument 'Get-WindowsFeature'.
+ CategoryInfo : InvalidArgument: (:) [Get-Module], ParameterBindingException
+ FullyQualifiedErrorId : PositionalParameterNotFound,Microsoft.PowerShell.Commands.GetModuleCommand
Any pointing in the right direction will be a great help !! thanks guys and girls.
You miss a ; after ServerManageralso, you probably mean Import-Moduleinstead of Get-Module:
Invoke-Command -ComputerName VM01 -ScriptBlock { Import-Module ServerManager; Get-WindowsFeature | Where-Object{$_.Installed -match "True" } | Select-Object -Property Name } -credential TestUser01

Adding Shared Printer to Remote Computer via Powershell

I am unable to run an invoke-command script to install printers on a remote machine. My code works locally, but as soon as I pipe it into Invoke-command, i get errors.
Local:
$Printer = "\\server1\printer1"
(New-Object -Com Wscript.Network).AddWindowsPrinterConnection($Printer)
And this adds the printer just fine. I can do this same command on the remote computer with no issues. But when i tried to execute the command remotely I have the issues.
Remote:
$compname = "computer"
$Printer = "\\server1\printer1"
Invoke-Command -ComputerName $CompName -Scriptblock {(New-Object -Com Wscript.Network).AddWindowsPrinterConnection('$Printer')}
Which returns the error "The printer name is invalid"
So I tried to see what the shell was sending to the remote computer with the following code, and everything in the write output looks good, but I still get errors:
Invoke-Command -ComputerName $CompName -Scriptblock {(New-Object -Com Wscript.Network).AddWindowsPrinterConnection('$Printer'); write-host "(New-Object -Com Wscript.Network).AddWindowsPrinterConnection('$Printer')"}
Output:
Exception calling "AddWindowsPrinterConnection" with "1" argument(s): "The printer name is invalid. (Exception from
HRESULT: 0x80070709)"
+ CategoryInfo : NotSpecified: (:) [], MethodInvocationException
+ FullyQualifiedErrorId : ComMethodTargetInvocation
+ PSComputerName : computer
(New-Object -Com Wscript.Network).AddWindowsPrinterConnection('\\server1\printer1')
Edit 1/5/2015
So I've tried Paul's code with a number of different entries to the argumentlist. All have not worked so far. i think the first 3 are closer to an answer.
-ArgumentList ""\\server1\printer1""
-ArgumentList ""'\\server1\printer1'""
-ArgumentList "\"\\server1\printer1""
Results in:
Invoke-Command : A positional parameter cannot be found that accepts argument '\\server1\printer1'.
At line:1 char:1
+ Invoke-Command -ComputerName $CompName -Scriptblock {(New-Object -Com Wscript.Ne ...
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo : InvalidArgument: (:) [Invoke-Command], ParameterBindingException
+ FullyQualifiedErrorId : PositionalParameterNotFound,Microsoft.PowerShell.Commands.InvokeCommandCommand
-ArgumentList "'\\server1\printer1'"
-ArgumentList \'"\\server1\printer1"'
-ArgumentList \""\\server1\printer1""
-ArgumentList \"\\server1\printer1"
Result in:
Exception calling "AddWindowsPrinterConnection" with "1" argument(s): "The printer name is invalid. (Exception from
HRESULT: 0x80070709)"
+ CategoryInfo : NotSpecified: (:) [], MethodInvocationException
+ FullyQualifiedErrorId : ComMethodTargetInvocation
+ PSComputerName : sso-mxl327082y
Try this:
Invoke-Command -ComputerName $CompName -Scriptblock {(New-Object -Com Wscript.Network).AddWindowsPrinterConnection($args[0]); write-host "(New-Object -Com Wscript.Network).AddWindowsPrinterConnection($($args[0]))"} -ArgumentList "\\server1\printer1"
I think it´s because your $printer variable is placed between single quotes, variables between single quotes are not interpreted by powershell. So the printername your function probably gets is "$printer".
In case you wonder it is printed out correctly in your write-host statement because here the single quotes are inside a string.
you need to use $Using:yourvar to pass variables to the scriptblock
$compname = "computer"
$Printer = "\\server1\printer1"
Invoke-Command -ComputerName $CompName -Scriptblock
{
(New-Object -Com Wscript.Network).AddWindowsPrinterConnection($Using:$Printer)
}
I think it's because of the so called 'double hop problem', where your authentication isn't transfered to the next remote computer which is sharing the printer.
I tried to solve similar problem using add-printer and following this article double hop problem solution.
However, although it works with get-childitem etc. it doesn't work with add-printer cmdlet.

Start-job resulting in null parameter

I'm trying to execute the following two lines of code in PowerShell v2.0 as a job, and am having trouble. I think I have the syntax right, but I can't get it to do what I think it should do, so I clearly am doing something wrong...
$report = <command line thing>
invoke-expression $report
These two lines work in PowerShell. But when I try to put it into a start-job command:
start-job -scriptblock {invoke-expression $report} -argumentlist $report | wait-job | receive-job
I get the following error:
Cannot bind argument to parameter 'Command' because it is null.
+ CategoryInfo : InvalidData: (:) [Invoke-Expression], ParameterBindingValidationException
+ FullyQualifiedErrorId : ParameterArgumentValidationErrorNullNotAllowed,Microsoft.PowerShell.Commands.InvokeExpre
ssionCommand
+ PSComputerName : localhost
I understand that error as saying that the argument I'm passing the invoke-expression is null, but, I'd thought that by passing $report in the -argumentlist param, it'd get through?
You cannot access $report directly unless you do:
-scriptblock {param($report) invoke-expression $report}
The param($report) part captures the $report variable passed in via -ArgumentList and makes it available for use inside the scriptblock.