Learning Points From PowerShell Scripting Games Event #2

Event 2 for the PowerShell Scripting Games 2013 has closed, here are a few learning points I picked up on from entries submitted.

1) Win32_Processor

This event is a bit of a sneaky one and if you haven’t been affected by the issue before then you may not know it. The particular issue I am referring to  here is that “The number of physical hyperthreading-enabled processors or the number of physical multicore processors is incorrectly reported in Windows Server 2003“. The issue is essentially this:

“Before you apply this hotfix, the WMI classes and the WMI properties exhibit the following behavior.

Win32_ComputerSystem

• The NumberOfLogicalProcessors property is not available.
• The NumberOfProcessors property returns the number of logical processors that are available on the system.

Win32_Processor

• The number of Win32_Processor instances that are returned is equal to the number of logical processors that are available on the system.
• The NumberOfCores property is not available.
• The NumberOfLogicalProcessors property is not available.

After you apply this hotfix, the WMI classes and the WMI properties exhibit the following behavior.

Win32_ComputerSystem

• The NumberOfProcessors property returns the number of physical processors that are available on the system.
• The NumberOfLogicalProcessors property returns the number of logical processors that are available on the system.

Win32_Processor

• The NumberOfLogicalProcessors property returns the number of logical processors on the current instance.
• The NumberOfCores property returns the number of cores on the current instance.
• The number of Win32_Processor instances that are returned is equal to the number of physical processors that are available on the system.

”

This tripped me up once when I received back inconsistent results from a large server estate where I was querying via WMI the number of processors per server. Luckily in that environment I was able to deploy the hotfix everywhere, but you might not be able to and potentially you may have further inconsistencies with Windows 2000 servers that can’t be fixed. This event contains a Windows 2000 server, so you may need to code around it.

The initial thought would be to check the OS version, but then you would have to detect if the hotfix was installed if it was a 2003 box – probably too much work. So what we could do is check for the NumberofCores property on a WMI query for Win32_Processor and if it doesn’t exist calculate the number of cores and sockets via other means. I haven’t tested this on Windows 2003 minus hotfix or 2000 yet, but you should be able to count the number of unique SocketDesignations returned to determine the number of sockets.

$Processors = Get-WmiObject Win32_Processor
if ($NoOfCores = $Processors.NumberOfCores){

$NoOfSockets = ($Processors | Measure-Object).Count
}
else {

$NoOfCores = 'N/A'
 $NoOfSockets = ($Processors | Select-Object SocketDesignation -Unique | Measure-Object).count
}

2) Using Add-Member when creating custom objects

Event 2 requires you to output results and it’s good to see many people doing this by creating their own objects to output. A number of entries use the Add-Member cmdlet to add properties to their custom object. While this is a perfectly valid way to do it and was the technically prescribed way  in PowerShell v1, I prefer a couple of different approaches and in this previous article explain why – mainly around performance. So I would do something like this (note that it does require PowerShell v3)

[pscustomobject] @{
 Name = $_.Name
 NoOfCores = $NoOfCores
 NoOfSockets = $NoOfSockets
#etc........
}

Hope this helps!