It came to my attention today that not everyone is spat out of the womb knowing how to test the network connection to a list of computers in PoSH. Some use cases for this one-liner could be…

• Testing guest connectivity on a set of vMotions/LiveMigrating VM’s
• ‘Monitoring’ the progress of automated/batch processes involving host restarts, for example VMware Update Manager host/guest patching
• Rudimentary confirmation of node system load when testing load-balanced farms, increased response time being a sign of significantly increased system pressure

It’s pretty easy to do this. The method relies on the ability of the Microsoft Management Powershell Module cmdlet, Test-Connection, to accept a comma-separated list of hostnames.

Example as follows:

Test-Connection -ComputerName TESTPC1,TESTPC2,TESTPC3 -Count 100

Example (redacted) output:

As you can see, the Test-Connection cmdlet is alternating between the three listed hosts.  The output is superior to our good friend ping, exposing more data in a tabulated presentation with failed connections even coming up in attention-grabbing red text! The cmdlet has several handy switches outlined here. In case the power of having an honest-to-goodness queriable object pumped out by your connectivity verifier, rather than a string dump, is not self evident (think scripting scenarios people!), you can find a decent overview at the computerperformance.co.uk site.

I needed to gather the system volume sizes for all the servers on our estate as part of a scoping exercise for a Microsoft DPM project. It seemed to me that WMI was probably the answer, and a brief Bing search discovered this script.

However, I didn’t want to manually type out a text file to feed it computer names. Nor do I trust our CMDB to be up to date enough that I could use that as a reference point. Therefore, I used the best CMDB in our org, Active Directory. One brief coding scripting session resulted in the PowerShell function below, which will recurse though OU’s nested below a base OU, specified by it’s LDAP path in the initial function call and captures all discovered computer object name values to a string object. It can be easily modified to capture whatever property you are interested in, so feel free to use & abuse. Enjoy!

Function GetCompsToString

{param ($baseou)

$ou = [ADSI] “$baseou”

foreach ($child in $ou.psbase.Children )

{

if ($child.ObjectCategory -like ‘*computer*’) {$strComputer +=$child.Name}

Elseif ($child.ObjectCategory -like ‘*Organizational-Unit*’) {GetCompsToString $child.path}

}

return $strComputer

}

$input = “LDAP://OU=BaseOU,DC=DOMAIN,DC=LOCAL”

$output = GetCompsToString $input

Thanks to Joachimm Naslander (http://social.technet.microsoft.com/Forums/en/winserverManagement/thread/a0cebabf-3fc9-49b0-be55-5e4ff3232b7b) for the core method I used.

NOTE!: I aim to use some more easily parsed way to publish code, so this will be retroactively enhanced.