The Invoke-Command is a very powerful way to run commands remotely.

When running commands remotely, you are essentially opening a new session on the target computer and outputting the results back to the local console.

In order to run commands remotely, we need to have a list of computers, in a string form. For our examples we'll save that list on a variable $ServerList To populate the variable we can do this:

$ServerList = "Server1", "Server2", "Server3", "Server4"

If the servers are listed on a notepad (one server per line), and saved as "c:\Temp\inventory.txt", we do this:

$ServerList= Get-Content -Path "c:\Temp\inventory.txt"

We will explore four very basic techniques.

1. Run a command remotely.
2. Run a saved file (script or function) remotely
3. Run a locally defined function remotely
4. Run successive commands remotely.

If we need to display the Event Viewer and see the last 10 event for system

invoke-command -ComputerName $ServerList -ScriptBlock {Get-EventLog -LogName System -Newest 10}

If we have a file, let's say C:\PS\Get-SQLParam.ps1, and we need to run it remotely, even if the remote servers can't access your local C:\ drive (in other words, you don't need to save it on a share) we do the following:

invoke-command -ComputerName $ServerList -FilePath c:\PS\Get-SQLParam.ps1

If we have a function, Get-WhoInstalledSQL, already dot-sourced on our console, and we need to run it remotely:

invoke-command -ComputerName $ServerList -ScriptBlock ${Function:\Get-SQLParam}

If we have a series of commands to run remotely, you can get crafty with "one liners" or put them on a file… or you can open a new session, a persisted one, like this:

$s = New-PSSession -ComputerName Server01, Server02, Server03
Invoke-Command -Session $s -ScriptBlock {$p = Get-Process PowerShell}
Invoke-Command -Session $s -ScriptBlock {$p.VirtualMemorySize}