Just wanted to clarify a question that sometimes customers ask…
How about if my Operations Manager agents are in maintenance mode and I want to run a task against them by using Operations Manager?
The answer is:
Yes they will run. Either the Agent tasks (below left) or the Console tasks (below right) would run as you could see on the screenshot.
What I would like to add is:
Bear in mind that tasks run with less priority and they could potentially be postponed on an Operations Manager 2007 R2 Management Group where the RMS is heavily processing Configuration or pushing out Management Packs.
How about in SCOM 2012?
Although there are now Resource Pools enabling for sharing the workload between their members the tasks are still less priority.
It's unlikely that on a SCOM 2012 Management Group you face the issue stated above however…
Based on a recent scenario I've faced on one of my customers which was still using SCOM2007 R2 my best recommendation would be:
If you want to trigger a very important task that should finish ASAP on an Agent or group of Agents, always ensure the required task workflow is performing well by triggering a simple task of the same type (Console or Agent) against them.
Only if successful trigger the critical one.
If you could not trigger any tasks at all: you should carefully review the capacity of your environment and overall performance of the Management Group.
The root causes could vary and further investigation would be required to identify the issue.
That would most probably include capturing Operations Manager trace logs on all the SCOM Management Servers, SCOM Gateways and the Agents involved.
Info on Diagnostic tracing in Operations Manager: http://support.microsoft.com/kb/942864
Hope this helps!