My thanks to Matt Taylor and Kevin Holman for their guidance!
Read on if these apply
Trying to start, update, or end SCOM MM
Get alerts when MM is updated
PowerShell only in your shop!
SCORCH in play but need to convert runbooks to straight PowerShell
Ran into issues using Set-SCOMMaintenanceMode, as the cmdlet doesn't put ALL the recursive classes under Windows Computer
Background
Set-SCOMMaintenanceMode cmdlet is actually “by design.” ☹
Start-SCOMMaintenanceMode assumes you want recursive action when you start maintenance mode…. So you pick a Windows Computer and it places the Windows Computer object (AND all contained objects) into MM.
Computer in MM
All contained objects in MM
However, the problem is that Set-SCOMMaintenancemode does not have an understanding of recursiveness. It changes the MM entry for the Windows Computer, but NOT all the contained objects. So they retain the original setting.
Health explorer looks like this, resulting in unwanted alerts
Details
NOTE these $Time and DateTime Method are dependent on the delay between running the commands
If you start MM, and wait 5 minutes, then update, the total MM duration will be ~20 minutes
# Start MM
$server = "Servername.FQDN"
$instance = (get-scomclass -DisplayName "Windows Computer" |Get-SCOMClassInstance | ? { $_.DisplayName -eq $server } )
$Time = (Get-Date).addMinutes(6)
Start-SCOMMaintenanceMode -Instance $Instance -EndTime $Time -Comment "Starting Maintenance Mode." -Reason "PlannedOther"
# Update MM
# Make sure you've put object in MM
$guid = $instance.id
$WCobj = Get-SCOMMonitoringObject -Id $guid
# 15 minutes in the future
$WCobj.UpdateMaintenanceMode([System.datetime]::Now.addminutes(15).touniversaltime(),[Microsoft.EnterpriseManagement.Monitoring.MaintenanceModeReason]::PlannedOther,[System.string]::"Adding 15 minutes to the end time.",[Microsoft.EnterpriseManagement.Common.TraversalDepth]::Recursive);
# Stop MM
# Make sure you've put object in MM
# Immediate
$WCobj.StopMaintenanceMode([System.DateTime]::Now.ToUniversalTime(),Microsoft.EnterpriseManagement.Common.TraversalDepth]::Recursive);
# 15 minutes in the future
$WCobj.StopMaintenanceMode([System.DateTime]::Now.addminutes(15).touniversaltime(),Microsoft.EnterpriseManagement.Common.TraversalDepth]::Recursive);
# 1 hour in the future
$WCobj.StopMaintenanceMode([System.DateTime]::Now.addhours(1).touniversaltime(),Microsoft.EnterpriseManagement.Common.TraversalDepth]::Recursive);
# Validate MM through Operations Manager Event ID’s 1215 and 1216 logged
get-eventlog -LogName "Operations Manager" | ? { $_.EventID -eq 1215 -OR $_.EventID -eq 1216 } |fl EventID,TimeGenerated,Message
# Error if object NOT in MM
Cannot find an overload for "UpdateMaintenanceMode" and the argument count: "1".
At line:1 char:1
+ $WCobj.UpdateMaintenanceMode(([System.datetime]::Now).addminutes(15). ...
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo : NotSpecified: (:) [], MethodException
+ FullyQualifiedErrorId : MethodCountCouldNotFindBest
PS C:Windowssystem32>
Testing System datetime
PS C:Windowssystem32> [System.datetime]::Now.addminutes(15)
Thursday, August 24, 2017 9:18:04 AM
PS C:Windowssystem32> ([System.datetime]::Now.addminutes(15)).touniversaltime()
Thursday, August 24, 2017 2:18:16 PM
References
SDK
DateTime Methods https://msdn.microsoft.com/en-us/library/system.datetime_methods(v=vs.110).aspx
MaintenanceModeReason Method https://msdn.microsoft.com/en-us/library/microsoft.enterprisemanagement.monitoring.maintenancemodereason.aspx
StopMaintenanceMode Method https://msdn.microsoft.com/en-us/library/microsoft.enterprisemanagement.monitoring.partialmonitoringobject.stopmaintenancemode.aspx
UpdateMaintenanceMode Method https://msdn.microsoft.com/en-us/library/bb424495.aspx
MM deluxe custom script https://gist.github.com/stegenfeldt/b3f044aa77894ed80d82f8849a48035b