There are two main ways to stop Alerts from being generated in VMware Aria Operations: deactivate them or put objects in maintenance mode. Deactivating them is the easy button, documentation can be found here. One way to do this is from Troubleshoot - Alert - Group by Definition.
Highly the Alert Definition - select ACTIONS - Deactivate, then deactivate in all policies or just selected policies. This goes into the relevant Policy/s and deactivates the Alert Definition. Of course you can do this directly via Configure - Policies - Policy Definition as well.
You can also put objects into Maintenance, which will stop data collection and alerting.
Above I'm putting a single Cluster into Maintenance, but I could have selected multiple Clusters as well, or anything other object. When you put an object into Maintenance, you define a schedule as well.
The schedule is quite nice, in that it prevents you from forgetting about an object in Maintenance.
There's another way to stop Alerts via Policies, and that's to create a Policy that has all Alert Definitions deactivated, and to add your object/types as necessary. First, create a Policy inherited from the Default.
Click CREATE POLICY.
Next, let's deactivate all Alert Definitions in this Policy via the Alerts and Symptoms tile.
Select the Object Type from the dropdown, I'm going to deactivate all the vSphere/vCenter Alert Definitions here, but you could do more/less, whatever you want. Let's start with Clusters, adjust the Page Size such that you get all of them on a single page, then Select All via the icon next to ACTIONS.
Once selected, go to ACTIONS - State - Deactivate.
We'll do this for all vCenter Object Types, but you can do this for as many Object Types as you want. Once complete, you can see I've deactivated 1477 Alert Definitions.
Now, to apply this Policy to an object/object type/custom group/etc, select the Groups and Objects tile.
Selecting the Objects drop down allows you to select a specific object, say for example I don't want any Alerts for Cluster WDC TVS, I'd select that Object and SAVE.
Back on the Policies page, you can now see our Stop Alerts Policy has a single Object in it. You can do the same using Custom Groups, say for example you want to stop Alerts for all ESXi Hosts in your environment.
Click SAVE.
Notice Groups and Objects now, it's got the new Custom Group as well as our previously defined object. But what if you want to stop Alerts against say a Cluster and all its descendants? Well, let's great a Custom Group for that! Go to Environments - Custom Groups - ADD. First thing we'll do as add the named Cluster to the Custom Group.
But how to include all ESXi Hosts, VMs, Datastores, etc in that Cluster? Adjust the criteria for inclusion by clicking the ADD ANOTHER CRITERIA SET and add the descendant ESXi Hosts.
Continue adding criteria sets until the Custom Group contains everything you want.
You can always click PREVIEW to confirm group membership. To stop alerts from the named Cluster and its descendants, just add your new Custom Group to your Stop Alerts Policy.
With this new Stop Alerts Policy in place, you can add/remove objects, objects types, custom groups, etc as you wish, which will stop all Alerts as defined in that Policy until they've been removed. This is a powerful way to prevent Alert spam. For more information on Aria Operations see our Tech Zone site.