Logical Disks Dynamic Group

So what do you do when a team comes to you and asks for different values for logical disk alerts?


Work smarter vs. harder!



Use Explicit groups

As an Admin, someone should not have to update groups every time a server or app changes in the environment.



Use Dynamic groups

One better, use regular expressions (see Kevin Holman’s blog if you need a refresher)



Great background information

Holman had a great article to make groups of logical disks

TechNet had some good example references in this wiki

Forum article where John Joyner (MVP) listed a way to make a dynamic group

Groups can consist of objects in a primary class and also includes Windows Computer attribute


How can this apply to  your environment?

Is there a unique attribute for the class you’ve chosen, or possibly to include Windows Computer class properties?

In my experience, the Windows Computer Class can be utilized to better specify the criteria, using Principal Name, NetBIOS name, etc.)



Let’s begin to see walk through the Logical Disk class attributes, and understand that we can look at the class, and the Windows Computer class.


From the SCOM Console

Click on the Monitoring Tab

Click on Discovered Inventory

On the Tasks pane (right hand pane), click on change target type

I chose Windows Server 2016 Logical Disk (corresponding for 2008,12 class structures exist)


Are there any unique class/object properties where we can differentiate?

Path stands out, possibly size

Display Name/Device Identifier/Device Name are of course the drive letter


Create a Dynamic group

From the SCOM Console

Click on the Authoring Tab

Click on Groups

On Task pane, click on ‘Create New group’


Name the group

Recommend naming convention – my example is TEAM Logical Disk group (where TEAM could be SQL, SharePoint, Exchange, Skype, etc.)

Don’t forget to add description comments to help the next guy who’s tracking down details!

Create Management pack, or add to the Team’s overrides or customizations management pack.


Click Next twice (to get to Dynamic Members tab)

Click Create/Edit Rules


Choose class

Our example was ‘Windows Server 2016 Logical Disk’

Click Add


Click the Property Drop down


Note the options – and refer back to your notes in the Discovered Inventory from the Monitoring Tab

The three D’s in the middle – Device Identifier, Device Name, and Device Description were all the drive letter

I chose Device Name as it seemed the logical choice


Click Insert + to add another property

Click again on the Class properties

Select the bottom choice – (Host=Windows Computer)

Select Principal name

In my case, the servers met a specific naming convention for the server name


In the Operator Column, choose ‘Matches regular expression’

In the Value field, enter your regular expression


My example is (?i)16[md]

Go back to my Discovered inventory output



Dissect the regular expression

(?i) case inclusive (don’t care upper or lower case – back to Unix roots!)

16m or 16d is in the server name


Click OK

Click Next twice to create group (and bypass Sub Groups, Excluded Members)

Click Create Group

Click Close



Verify expression

From the Authoring pane

Click on the Group and either right click ‘View Group members’, or in the task pane, click ‘View Group members’

Practice using regular expressions to get the desired results!



Now it’s time to go off and override the monitor for the newly created group!


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