Enable SCOM subscriptions with Powershell with “Fewer messages”

This is one widely known “inconvenience” with working with Powershell to manage your subscriptions in a big SCOM environment. Consider the following widely common scenario:

You have a SCOM environment with a fairly large number of subscriptions. You have a planned maintenance scheduled, and so you plan to disable all your subscriptions so that the support teams aren’t bothered with unnecessary alerts. There is a simple quick way of doing this:

Import-Module OperationsManager
Get-SCOMNotificationSubscription | Disable-SCOMNotificationSubscription

This will disable all your subscriptions and stop sending notifications out. This is simple enough. The issue lies with enabling them back. The catch here is when you enable the subscription using Powershell, you start getting all the notifications that were “cached” during the time of the maintenance mode, and your support teams are bombarded with tens or even hundreds of such spam notifications. This is because when you enable the subscriptions with Powershell, it enabled it using the default option of “More messages”. Moreover, there is no apparent parameter/switch to change it to “Fewer messages”.

Get-SCOMNotificationSubscription | Enable-SCOMNotificationSubscription

If you are not familiar with these two options, here’s what they mean:

More Messages: This option means all the notifications that were cached since the subscription was disabled are forwarded to subscribers.

Fewer Messages: This option means only the notifications that are generated after the subscription was re-enabled are forwarded to the subscribers.

This discussion was actually happening a few days ago on the SCOM Community Gitter Lobby (make sure to join!), and Dimitry K. suggested an excellent workaround on this issue (Kudos, Dimitry!). There’s no parameter in the cmdlet to switch options but you can actually do this using a method. Here’s the code:

$sub = Get-SCOMNotificationSubscription | where {$_.displayname -like "SUBSCRIPTION_NAME"}
$sub.Enabled = $true
$sub.Update($true)

Note the last line – $sub.Update($true)

The value you pass to this method actually determines the option to choose more or fewer messages. If you choose Update($true), it is equivalent to fewer messages, and if you choose Update($false), it is equivalent to more messages in the GUI.

Hope this helps, and save you and your support teams from a bunch of spam emails!

Cheers