Using PowerShell with System Center 2012 R2 Configuration Manager Maintenance Tasks

If you have worked with the PowerShell Set-CMSiteMaintenanceTask and Get-CMSiteMaintenanceTask you most likely have already mapped the task name parameter to the actual task name. 

At this time the Get-CMSiteMaintenanceTask reference page on TechNet doesn’t list the Maintenance Task name however, you can reference the SMS_SCI_SQLTask Server WMI Class of the Configuration Manager SDK to get them.

For those that haven’t used the Set-CMSiteMaintenanceTask and Get-CMSiteMaintenanceTask you can use this table for the task names to save some time instead of figuring it out with a trial and error process. I wouldn’t be surprised if these were changed in the future to use a common set of task names for each cmdlet.

Current Bugs

Currently, there are a couple of bugs with each cmdlet. The Get-CMSiteMaintenanceTask doesn’t retrieve the BeginTime and LatestBeginTime properties. The Set-CMSiteMaintenanceTask requires the –DeviceName argument set although it only applies to the BackupSiteServer. You can set the argument to “ “ as a workaround to the bug. (e.g. –DeviceName “ “)

Getting BeginTime and LatestBeginTime

To get the BeginTime and LatestBeginTime properties of a task you can query the SMS_SCI_SQLTask Server WMI Class then convert the DateTime value to a hh:mm string format.

This is a sample wmi query to get the Delete Obsolete Alerts tasks:

$MT = gwmi -Namespace root\sms\site_<SiteCode> -Query "Select * from SMS_SCI_SQLTask Where SiteCode='<SiteCode>' and TaskName = 'Delete Obsolete Alerts'" -ComputerName <computername>
To output the begintime run($MT).BeginTime

When displaying either the BeginTime and LatestBeginTime properties it’ll be returned in a WMI datetime format such as 00000000050000.000000+*** however, when using the[System.Management.ManagementDateTimeConverter]::ToDateTime()method to convert it, it will throw an error. One way of getting the hours and minutes needed is parse it as a string. This function will take the datetime format and return an hh:mm string format.

Function Convert-WMITime{
[CmdletBinding()]
Param(
[Parameter(Mandatory=$true)]
[Alias("WT")] [string]$CIMdatetime)
return $CIMdatetime.Substring(8,2)+":"+$CIMdatetime.substring(10,2)
}

Getting the Days of Week

The DaysOfWeek for each task is stored as a UInt32 value however, the name of the days is represented as binary. The name of the days are required for the Set-CMSiteMaintenanceTask cmdlet and is just easier to read. 

One method of getting the day names is to convert the decimal value to binary then iterate the binary bits to create an array of day names. 

This table can help visualize the tasks that need to be done.

Converting the decimal to binary can be used with the .Net Convert method. Since we are working with up to 7 bits (one for each day of the week) it should be padded to the left and included 0’s for empty spaces. For instance, Thursday is the decimal value of 16 and binary value of 10000. Extra zero’s will be added to the left to ensure there are 7 values. This will in turn become 0010000.

$bDays = [Convert]::ToString($MT. DaysOfWeek,2).PadLeft(7,'0')

Match 0010000 with the above table, wherever the bit is set to 1 then add that day to an array.

$aDays = @()
$aDayNames = @("Saturday", "Friday", "Thursday", "Wednesday", "Tuesday", "Monday", "Sunday")
$bDays = $bDays[0..$bDays.length]

for($i=0;$i -lt $bDays.Length;$i++){
if($bDays[$i] -eq "1"){$aDays = $aDays + $($aDayNames[$i])}
{

This is a complete function that can be used to return the DaysOfWeek UInt32 value and return an array of day names:

Function Convert-DecimaltoDays{
[CmdletBinding()]
Param(
[Parameter(Mandatory=$true)]
[Alias("D")]
[string]$Days
)
$aDays = @()
$aDayNames = @("Saturday", "Friday", "Thursday", "Wednesday", "Tuesday", "Monday", "Sunday")

     $bDays = [Convert]::ToString($Days,2).PadLeft(7,'0')
$bDays = $bDays[0..$bDays.length]
for($i=0;$i -lt $bDays.Length;$i++){
if($bDays[$i] -eq "1"){$aDays = $aDays + $($aDayNames[$i])}
}
return $aDays
}