| title | ms.date | keywords | description | ms.topic | author | manager | ms.prod |
|---|---|---|---|---|---|---|---|
Troubleshooting DSC |
2016-05-16 |
powershell,DSC |
article |
eslesar |
dongill |
powershell |
Applies To: Windows PowerShell 4.0, Windows PowerShell 5.0
This topic describes methods for getting your Desired State Configuration (DSC) scripts to run without error. By using logs effectively to track down errors, and understanding how to recycle the cache to see the immediate results of your resource changes, you’ll be able to troubleshoot DSC more effectively. These technics are discussed in two sections:
- My script won’t run: Using DSC logs to diagnose script errors
- My resources won’t update: How to reset the cache
Like all Windows software, DSC records errors and events in logs that can be viewed from the Event Viewer. Examining these logs can help you understand why a particular operation failed, and how to prevent failure in the future. Writing configuration scripts can be tricky, so to make tracking errors easier as you author, use the DSC Log resource to track the progress of your configuration in the DSC Analytic event log.
In Event Viewer, DSC events are in: Applications and Services Logs/Microsoft/Windows/Desired State Configuration
The corresponding PowerShell cmdlet, Get-WinEvent, can also be run to view the event logs:
PS C:\> Get-WinEvent -LogName "Microsoft-Windows-Dsc/Operational"
ProviderName: Microsoft-Windows-DSC
TimeCreated Id LevelDisplayName Message
----------- -- ---------------- -------
11/17/2014 10:27:23 PM 4102 Information Job {02C38626-D95A-47F1-9DA2-C1D44A7128E7} :
As shown above, DSC’s primary log name is Microsoft->Windows->DSC (other log names under Windows are not shown here for brevity). The primary name is appended to the channel name to create the complete log name. The DSC engine writes mainly into three types of logs: Operational, Analytic, and Debug logs. Since the analytic and debug logs are turned off by default, you should enable them in Event Viewer. To do this, open Event Viewer by typing Show-EventLog in Windows PowerShell; or, click the Start button, click Control Panel, click Administrative Tools, and then click Event Viewer. On the View menu in Event viewer, click Show Analytic and Debug Logs. The log name for the analytic channel is Microsoft-Windows-Dsc/Analytic, and the debug channel is Microsoft-Windows-Dsc/Debug. You could also use the wevtutil utility to enable the logs, as shown in the following example.
wevtutil.exe set-log “Microsoft-Windows-Dsc/Analytic” /q:true /e:trueDSC logs are split over the three log channels based on the importance of the message. The operational log in DSC contains all error messages, and can be used to identify a problem. The analytic log has a higher volume of events, and can identify where error(s) occurred. This channel also contains verbose messages (if any). The debug log contains logs that can help you understand how the errors occurred. DSC event messages are structured such that every event message begins with a job ID that uniquely represents a DSC operation. The example below attempts to obtain the message from the first event logged into the operational DSC log.
PS C:\> $AllDscOpEvents = Get-WinEvent -LogName "Microsoft-Windows-Dsc/Operational"
PS C:\> $FirstOperationalEvent = $AllDscOpEvents[0]
PS C:\> $FirstOperationalEvent.Message
Job {02C38626-D95A-47F1-9DA2-C1D44A7128E7} :
Consistency engine was run successfully. DSC events are logged in a particular structure that enables the user to aggregate events from one DSC job. The structure is as follows:
Job ID :
DSC event logs contain events generated by various DSC operations. However, you’ll usually be concerned with the detail about just one particular operation. All DSC logs can be grouped by the job ID property that is unique for every DSC operation. The job ID is displayed as the first property value in all DSC events. The following steps explain how to accumulate all events in a grouped array structure.
<##########################################################################
Step 1 : Enable analytic and debug DSC channels (Operational channel is enabled by default)
###########################################################################>
wevtutil.exe set-log “Microsoft-Windows-Dsc/Analytic” /q:true /e:true
wevtutil.exe set-log “Microsoft-Windows-Dsc/Debug” /q:True /e:true
<##########################################################################
Step 2 : Perform the required DSC operation (Below is an example, you could run any DSC operation instead)
###########################################################################>
Get-DscLocalConfigurationManager
<##########################################################################
Step 3 : Collect all DSC Logs, from the Analytic, Debug and Operational channels
###########################################################################>
$DscEvents=[System.Array](Get-WinEvent "Microsoft-Windows-Dsc/Operational") `
+ [System.Array](Get-WinEvent "Microsoft-Windows-Dsc/Analytic" -Oldest) `
+ [System.Array](Get-WinEvent "Microsoft-Windows-Dsc/Debug" -Oldest)
<##########################################################################
Step 4 : Group all logs based on the job ID
###########################################################################>
$SeparateDscOperations = $DscEvents | Group {$_.Properties[0].value} Here, the variable $SeparateDscOperations contains logs grouped by the job IDs. Each array element of this variable represents a group of events logged by a different DSC operation, allowing access to more information about the logs.
PS C:\> $SeparateDscOperations
Count Name Group
----- ---- -----
48 {1A776B6A-5BAC-11E3-BF... {System.Diagnostics.Eventing.Reader.EventLogRecord, System.Diagnostics....
40 {E557E999-5BA8-11E3-BF... {System.Diagnostics.Eventing.Reader.EventLogRecord, System.Diagnostics....
PS C:\> $SeparateDscOperations[0].Group
ProviderName: Microsoft-Windows-DSC
TimeCreated Id LevelDisplayName Message
----------- -- ---------------- -------
12/2/2013 3:47:29 PM 4115 Information Job {1A776B6A-5BAC-11E3-BF41-00155D553612} : ...
12/2/2013 3:47:29 PM 4198 Information Job {1A776B6A-5BAC-11E3-BF41-00155D553612} : ...
12/2/2013 3:47:29 PM 4114 Information Job {1A776B6A-5BAC-11E3-BF41-00155D553612} : ...
12/2/2013 3:47:29 PM 4102 Information Job {1A776B6A-5BAC-11E3-BF41-00155D553612} : ...
12/2/2013 3:47:29 PM 4098 Warning Job {1A776B6A-5BAC-11E3-BF41-00155D553612} : ...
12/2/2013 3:47:29 PM 4098 Warning Job {1A776B6A-5BAC-11E3-BF41-00155D553612} : ...
12/2/2013 3:47:29 PM 4176 Information Job {1A776B6A-5BAC-11E3-BF41-00155D553612} : ...
12/2/2013 3:47:29 PM 4182 Information Job {1A776B6A-5BAC-11E3-BF41-00155D553612} : ...
12/2/2013 3:47:29 PM 4182 Information Job {1A776B6A-5BAC-11E3-BF41-00155D553612} : ...
12/2/2013 3:47:29 PM 4182 Information Job {1A776B6A-5BAC-11E3-BF41-00155D553612} : ...
12/2/2013 3:47:29 PM 4182 Information Job {1A776B6A-5BAC-11E3-BF41-00155D553612} : ...
12/2/2013 3:47:29 PM 4182 Information Job {1A776B6A-5BAC-11E3-BF41-00155D553612} : ...
12/2/2013 3:47:29 PM 4182 Information Job {1A776B6A-5BAC-11E3-BF41-00155D553612} : ...
12/2/2013 3:47:29 PM 4182 Information Job {1A776B6A-5BAC-11E3-BF41-00155D553612} : ...
12/2/2013 3:47:29 PM 4182 Information Job {1A776B6A-5BAC-11E3-BF41-00155D553612} : ...
You can extract the data in the variable $SeparateDscOperations using Where-Object. Following are five scenarios in which you might want to extract data for troubleshooting DSC:
All events have severity levels. This information can be used to identify the error events:
PS C:\> $SeparateDscOperations | Where-Object {$_.Group.LevelDisplayName -contains "Error"}
Count Name Group
----- ---- -----
38 {5BCA8BE7-5BB6-11E3-BF... {System.Diagnostics.Eventing.Reader.EventLogRecord, System.Diagnostics....
TimeCreated, a property of every Windows event, states the time the event was created. Comparing this property with a particular date/time object can be used to filter all events:
PS C:\> $DateLatest = (Get-Date).AddMinutes(-30)
PS C:\> $SeparateDscOperations | Where-Object {$_.Group.TimeCreated -gt $DateLatest}
Count Name Group
----- ---- -----
1 {6CEC5B09-5BB0-11E3-BF... {System.Diagnostics.Eventing.Reader.EventLogRecord} The latest operation is stored in the first index of the array group $SeparateDscOperations. Querying the group’s messages for index 0 returns all messages for the latest operation:
PS C:\> $SeparateDscOperations[0].Group.Message
Job {5BCA8BE7-5BB6-11E3-BF41-00155D553612} :
Running consistency engine.
Job {1A776B6A-5BAC-11E3-BF41-00155D553612} :
Configuration is sent from computer NULL by user sid S-1-5-18.
Job {1A776B6A-5BAC-11E3-BF41-00155D553612} :
Displaying messages from built-in DSC resources:
WMI channel 1
ResourceID:
Message : [INCH-VM]: [] Starting consistency engine.
Job {1A776B6A-5BAC-11E3-BF41-00155D553612} :
Displaying messages from built-in DSC resources:
WMI channel 1
ResourceID:
Message : [INCH-VM]: [] Consistency check completed.
$SeparateDscOperations[0].Group contains a set of events for the latest operation. Run the Where-Object cmdlet to filter the events based on their level display name. Results are stored in the $myFailedEvent variable, which can be further dissected to get the event message:
PS C:\> $myFailedEvent = ($SeparateDscOperations[0].Group | Where-Object {$_.LevelDisplayName -eq "Error"})
PS C:\> $myFailedEvent.Message
Job {5BCA8BE7-5BB6-11E3-BF41-00155D553612} :
DSC Engine Error :
Error Message Current configuration does not exist. Execute Start-DscConfiguration command with -Path pa
rameter to specify a configuration file and create a current configuration first.
Error Code : 1 $SeparateDscOperations is an array of groups, each of which has the name as the unique job ID. By running the Where-Object cmdlet, you can extract those groups of events that have a particular job ID:
PS C:\> ($SeparateDscOperations | Where-Object {$_.Name -eq $jobX} ).Group
ProviderName: Microsoft-Windows-DSC
TimeCreated Id LevelDisplayName Message
----------- -- ---------------- -------
12/2/2013 4:33:24 PM 4102 Information Job {847A5619-5BB2-11E3-BF41-00155D553612} : ...
12/2/2013 4:33:24 PM 4168 Information Job {847A5619-5BB2-11E3-BF41-00155D553612} : ...
12/2/2013 4:33:24 PM 4146 Information Job {847A5619-5BB2-11E3-BF41-00155D553612} : ...
12/2/2013 4:33:24 PM 4120 Information Job {847A5619-5BB2-11E3-BF41-00155D553612} : ... xDscDiagnostics is a PowerShell module that consists of several functions that can help analyze DSC failures on your machine. These functions
can help you identify all local events from past DSC operations, or DSC events on remote computers (with valid credentials). Here, the term DSC operation is used to define a single unique
DSC execution from its start to its end. For example, Test-DscConfiguration would be a separate DSC operation. Similarly, every other cmdlet in DSC (such as Get-DscConfiguration,
Start-DscConfiguration, etc.) could each be identified as separate DSC operations. The functions are explained at xDscDiagnostics.
Help is available by running Get-Help <cmdlet name>.
The Get-xDscOperation function lets you find the results of the DSC operations that run on one or multiple computers, and returns an object that contains the collection of events produced by each DSC operation.
For example, in the following output, three commands were run. The first one passed, and the other two failed. These results are summarized in the output of Get-xDscOperation.
PS C:\DiagnosticsTest> Get-xDscOperation
ComputerName SequenceId TimeCreated Result JobID AllEvents
------------ ---------- ----------- ------ ----- ---------
SRV1 1 6/23/2016 9:37:52 AM Failure 9701aadf-395e-11e6-9165-00155d390509 {@{Message=; TimeC...
SRV1 2 6/23/2016 9:36:54 AM Failure 7e8e2d6e-395c-11e6-9165-00155d390509 {@{Message=; TimeC...
SRV1 3 6/23/2016 9:36:54 AM Success af72c6aa-3960-11e6-9165-00155d390509 {@{Message=Operati...
You can also specify that you want only results for the most recent operations by using the Newest parameter:
PS C:\DiagnosticsTest> Get-xDscOperation -Newest 5
ComputerName SequenceId TimeCreated Result JobID AllEvents
------------ ---------- ----------- ------ ----- ---------
SRV1 1 6/23/2016 4:36:54 PM Success {@{Message=; TimeC...
SRV1 2 6/23/2016 4:36:54 PM Success 5c06402b-399b-11e6-9165-00155d390509 {@{Message=Operati...
SRV1 3 6/23/2016 4:36:54 PM Success {@{Message=; TimeC...
SRV1 4 6/23/2016 4:36:54 PM Success 5c06402a-399b-11e6-9165-00155d390509 {@{Message=Operati...
SRV1 5 6/23/2016 4:36:51 PM Success {@{Message=; TimeC...The Trace-xDscOperation1 cmdlet returns an object containing a collection of events, their event types, and the message output generated from a particular DSC operation. Typically, when you find a failure in any of the operations using Get-xDscOperation`, you would trace that operation to find out which of the events caused a failure.
Use the SequenceID parameter to get the events for a specific operation for a specific computer. For example, if you specify a SequenceID of 9, Trace-xDscOperaion get the
trace for the DSC operation that was 9th from the last operation:
PS C:\DiagnosticsTest> Trace-xDscOperation -SequenceID 9
ComputerName EventType TimeCreated Message
------------ --------- ----------- -------
SRV1 OPERATIONAL 6/24/2016 10:51:52 AM Operation Consistency Check or Pull started by user sid S-1-5-20 from computer NULL.
SRV1 OPERATIONAL 6/24/2016 10:51:52 AM Running consistency engine.
SRV1 OPERATIONAL 6/24/2016 10:51:52 AM The local configuration manager is updating the PSModulePath to WindowsPowerShell\Modules;C:\Prog...
SRV1 OPERATIONAL 6/24/2016 10:51:53 AM Resource execution sequence :: [WindowsFeature]DSCServiceFeature, [xDSCWebService]PSDSCPullServer.
SRV1 OPERATIONAL 6/24/2016 10:51:54 AM Consistency engine was run successfully.
SRV1 OPERATIONAL 6/24/2016 10:51:54 AM Job runs under the following LCM setting. ...
SRV1 OPERATIONAL 6/24/2016 10:51:54 AM Operation Consistency Check or Pull completed successfully. Pass the GUID assigned to a specific DSC operation (as returned by the Get-xDscOperation cmldet) to get the event details for that DSC operation:
PS C:\DiagnosticsTest> Trace-xDscOperation -JobID 9e0bfb6b-3a3a-11e6-9165-00155d390509
ComputerName EventType TimeCreated Message
------------ --------- ----------- -------
SRV1 OPERATIONAL 6/24/2016 11:36:56 AM Operation Consistency Check or Pull started by user sid S-1-5-20 from computer NULL.
SRV1 ANALYTIC 6/24/2016 11:36:56 AM Deleting file from C:\Windows\System32\Configuration\DSCEngineCache.mof
SRV1 OPERATIONAL 6/24/2016 11:36:56 AM Running consistency engine.
SRV1 VERBOSE 6/24/2016 11:36:56 AM [SRV1]: [] Starting consistency engine.
SRV1 ANALYTIC 6/24/2016 11:36:56 AM Applying configuration from C:\Windows\System32\Configuration\Current.mof.
SRV1 ANALYTIC 6/24/2016 11:36:56 AM Parsing the configuration to apply.
SRV1 OPERATIONAL 6/24/2016 11:36:56 AM Resource execution sequence :: [WindowsFeature]DSCServiceFeature, [xDSCWebService]PSDSCPullServer.
SRV1 VERBOSE 6/24/2016 11:36:56 AM [SRV1]: LCM: [ Start Resource ] [[WindowsFeature]DSCServiceFeature]
SRV1 ANALYTIC 6/24/2016 11:36:56 AM Executing operations for PS DSC resource MSFT_RoleResource with resource name [WindowsFeature]DSC...
SRV1 VERBOSE 6/24/2016 11:36:56 AM [SRV1]: LCM: [ Start Test ] [[WindowsFeature]DSCServiceFeature]
SRV1 VERBOSE 6/24/2016 11:36:56 AM [SRV1]: [[WindowsFeature]DSCServiceFeature] The operation 'Get...
SRV1 VERBOSE 6/24/2016 11:36:56 AM [SRV1]: [[WindowsFeature]DSCServiceFeature] The operation 'Get...
SRV1 VERBOSE 6/24/2016 11:36:56 AM [SRV1]: LCM: [ End Test ] [[WindowsFeature]DSCServiceFeature] True in 0.3130 sec...
SRV1 VERBOSE 6/24/2016 11:36:56 AM [SRV1]: LCM: [ End Resource ] [[WindowsFeature]DSCServiceFeature]
SRV1 VERBOSE 6/24/2016 11:36:56 AM [SRV1]: LCM: [ Start Resource ] [[xDSCWebService]PSDSCPullServer]
SRV1 ANALYTIC 6/24/2016 11:36:56 AM Executing operations for PS DSC resource MSFT_xDSCWebService with resource name [xDSCWebService]P...
SRV1 VERBOSE 6/24/2016 11:36:56 AM [SRV1]: LCM: [ Start Test ] [[xDSCWebService]PSDSCPullServer]
SRV1 VERBOSE 6/24/2016 11:36:56 AM [SRV1]: [[xDSCWebService]PSDSCPullServer] Check Ensure
SRV1 VERBOSE 6/24/2016 11:36:56 AM [SRV1]: [[xDSCWebService]PSDSCPullServer] Check Port
SRV1 VERBOSE 6/24/2016 11:36:56 AM [SRV1]: [[xDSCWebService]PSDSCPullServer] Check Physical Path ...
SRV1 VERBOSE 6/24/2016 11:36:56 AM [SRV1]: [[xDSCWebService]PSDSCPullServer] Check State
SRV1 VERBOSE 6/24/2016 11:36:56 AM [SRV1]: [[xDSCWebService]PSDSCPullServer] Get Full Path for We...
SRV1 VERBOSE 6/24/2016 11:36:56 AM [SRV1]: LCM: [ End Test ] [[xDSCWebService]PSDSCPullServer] True in 0.0160 seconds.
SRV1 VERBOSE 6/24/2016 11:36:56 AM [SRV1]: LCM: [ End Resource ] [[xDSCWebService]PSDSCPullServer]
SRV1 VERBOSE 6/24/2016 11:36:56 AM [SRV1]: [] Consistency check completed.
SRV1 ANALYTIC 6/24/2016 11:36:56 AM Deleting file from C:\Windows\System32\Configuration\DSCEngineCache.mof
SRV1 OPERATIONAL 6/24/2016 11:36:56 AM Consistency engine was run successfully.
SRV1 OPERATIONAL 6/24/2016 11:36:56 AM Job runs under the following LCM setting. ...
SRV1 OPERATIONAL 6/24/2016 11:36:56 AM Operation Consistency Check or Pull completed successfully.
SRV1 ANALYTIC 6/24/2016 11:36:56 AM Deleting file from C:\Windows\System32\Configuration\DSCEngineCache.mofNote that, since Trace-xDscOperation aggregates events from the Analytic, Debug, and Operational logs, it will prompt you to enable these logs as described above.
Alternately, you can gather information on the events by saving the output of Trace-xDscOperation into a variable. You can use the following commands to display all the events for a
particular DSC operation.
PS C:\DiagnosticsTest> $Trace = Trace-xDscOperation -SequenceID 4
PS C:\DiagnosticsTest> $Trace.EventThis will display the same results as the Get-WinEvent cmdlet, such as in the output below:
ProviderName: Microsoft-Windows-DSC
TimeCreated Id LevelDisplayName Message
----------- -- ---------------- -------
6/23/2016 1:36:53 AM 4312 Information The DscTimer is running LCM method PerformRequiredConfigurationChecks with the flag set to 5.
6/23/2016 1:36:53 AM 4343 Information The DscTimer has successfully run LCM method PerformRequiredConfigurationChecks with flag 5.
6/23/2016 2:07:00 AM 4312 Information The DscTimer is running LCM method PerformRequiredConfigurationChecks with the flag set to 5.
6/23/2016 2:07:01 AM 4343 Information The DscTimer has successfully run LCM method PerformRequiredConfigurationChecks with flag 5.
6/23/2016 2:36:55 AM 4312 Information The DscTimer is running LCM method PerformRequiredConfigurationChecks with the flag set to 5.
6/23/2016 2:36:56 AM 4343 Information The DscTimer has successfully run LCM method PerformRequiredConfigurationChecks with flag 5.
6/23/2016 3:06:55 AM 4312 Information The DscTimer is running LCM method PerformRequiredConfigurationChecks with the flag set to 5.
6/23/2016 3:06:55 AM 4343 Information The DscTimer has successfully run LCM method PerformRequiredConfigurationChecks with flag 5.
6/23/2016 3:36:55 AM 4312 Information The DscTimer is running LCM method PerformRequiredConfigurationChecks with the flag set to 5.
6/23/2016 3:36:55 AM 4343 Information The DscTimer has successfully run LCM method PerformRequiredConfigurationChecks with flag 5.
6/23/2016 4:06:53 AM 4312 Information The DscTimer is running LCM method PerformRequiredConfigurationChecks with the flag set to 5.
6/23/2016 4:06:53 AM 4343 Information The DscTimer has successfully run LCM method PerformRequiredConfigurationChecks with flag 5.
6/23/2016 4:36:52 AM 4312 Information The DscTimer is running LCM method PerformRequiredConfigurationChecks with the flag set to 5.
6/23/2016 4:36:53 AM 4343 Information The DscTimer has successfully run LCM method PerformRequiredConfigurationChecks with flag 5.
6/23/2016 5:06:52 AM 4312 Information The DscTimer is running LCM method PerformRequiredConfigurationChecks with the flag set to 5.
6/23/2016 5:06:53 AM 4343 Information The DscTimer has successfully run LCM method PerformRequiredConfigurationChecks with flag 5.
6/23/2016 5:36:54 AM 4312 Information The DscTimer is running LCM method PerformRequiredConfigurationChecks with the flag set to 5.
6/23/2016 5:36:54 AM 4343 Information The DscTimer has successfully run LCM method PerformRequiredConfigurationChecks with flag 5.
6/23/2016 6:06:52 AM 4312 Information The DscTimer is running LCM method PerformRequiredConfigurationChecks with the flag set to 5.
6/23/2016 6:06:53 AM 4343 Information The DscTimer has successfully run LCM method PerformRequiredConfigurationChecks with flag 5.
6/23/2016 6:36:56 AM 4312 Information The DscTimer is running LCM method PerformRequiredConfigurationChecks with the flag set to 5.
6/23/2016 6:36:57 AM 4343 Information The DscTimer has successfully run LCM method PerformRequiredConfigurationChecks with flag 5.
6/23/2016 7:06:52 AM 4312 Information The DscTimer is running LCM method PerformRequiredConfigurationChecks with the flag set to 5.
6/23/2016 7:06:53 AM 4343 Information The DscTimer has successfully run LCM method PerformRequiredConfigurationChecks with flag 5.
6/23/2016 7:36:53 AM 4312 Information The DscTimer is running LCM method PerformRequiredConfigurationChecks with the flag set to 5.
6/23/2016 7:36:54 AM 4343 Information The DscTimer has successfully run LCM method PerformRequiredConfigurationChecks with flag 5.
6/23/2016 8:06:54 AM 4312 Information The DscTimer is running LCM method PerformRequiredConfigurationChecks with the flag set to 5.Ideally, you would first use Get-xDscOperation to list out the last few DSC configuration runs on your machines. Following this, you can examine any single operation (using its SequenceID or JobID) with Trace-xDscOperation to discover what it did behind the scenes.
Use the ComputerName parameter of the Trace-xDscOperation cmdlet to get the event details on a remote computer. Before you can do this, you have to create a firewall rule to allow
remote administration on the remote computer:
New-NetFirewallRule -Name "Service RemoteAdmin" -DisplayName "Remote" -Action AllowNow you can specify that computer in your call to Trace-xDscOperation:
PS C:\DiagnosticsTest> Trace-xDscOperation -ComputerName SRV2 -Credential Get-Credential -SequenceID 5
ComputerName EventType TimeCreated Message
------------ --------- ----------- -------
SRV2 OPERATIONAL 6/24/2016 11:36:56 AM Operation Consistency Check or Pull started by user sid S-1-5-20 f...
SRV2 ANALYTIC 6/24/2016 11:36:56 AM Deleting file from C:\Windows\System32\Configuration\DSCEngineCach...
SRV2 OPERATIONAL 6/24/2016 11:36:56 AM Running consistency engine.
SRV2 VERBOSE 6/24/2016 11:36:56 AM [SRV2]: [] Starting consistency...
SRV2 ANALYTIC 6/24/2016 11:36:56 AM Applying configuration from C:\Windows\System32\Configuration\Curr...
SRV2 ANALYTIC 6/24/2016 11:36:56 AM Parsing the configuration to apply.
SRV2 OPERATIONAL 6/24/2016 11:36:56 AM Resource execution sequence :: [WindowsFeature]DSCServiceFeature,...
SRV2 VERBOSE 6/24/2016 11:36:56 AM [SRV2]: LCM: [ Start Resource ] [[WindowsFeature]DSCSer...
SRV2 ANALYTIC 6/24/2016 11:36:56 AM Executing operations for PS DSC resource MSFT_RoleResource with re...
SRV2 VERBOSE 6/24/2016 11:36:56 AM [SRV2]: LCM: [ Start Test ] [[WindowsFeature]DSCSer...
SRV2 VERBOSE 6/24/2016 11:36:56 AM [SRV2]: [[WindowsFeature]DSCSer...
SRV2 VERBOSE 6/24/2016 11:36:56 AM [SRV2]: [[WindowsFeature]DSCSer...
SRV2 VERBOSE 6/24/2016 11:36:56 AM [SRV2]: LCM: [ End Test ] [[WindowsFeature]DSCSer...
SRV2 VERBOSE 6/24/2016 11:36:56 AM [SRV2]: LCM: [ End Resource ] [[WindowsFeature]DSCSer...
SRV2 VERBOSE 6/24/2016 11:36:56 AM [SRV2]: LCM: [ Start Resource ] [[xDSCWebService]PSDSCP...
SRV2 ANALYTIC 6/24/2016 11:36:56 AM Executing operations for PS DSC resource MSFT_xDSCWebService with ...
SRV2 VERBOSE 6/24/2016 11:36:56 AM [SRV2]: LCM: [ Start Test ] [[xDSCWebService]PSDSCP...
SRV2 VERBOSE 6/24/2016 11:36:56 AM [SRV2]: [[xDSCWebService]PSDSCP...
SRV2 VERBOSE 6/24/2016 11:36:56 AM [SRV2]: [[xDSCWebService]PSDSCP...
SRV2 VERBOSE 6/24/2016 11:36:56 AM [SRV2]: [[xDSCWebService]PSDSCP...
SRV2 VERBOSE 6/24/2016 11:36:56 AM [SRV2]: [[xDSCWebService]PSDSCP...
SRV2 VERBOSE 6/24/2016 11:36:56 AM [SRV2]: [[xDSCWebService]PSDSCP...
SRV2 VERBOSE 6/24/2016 11:36:56 AM [SRV2]: LCM: [ End Test ] [[xDSCWebService]PSDSCP...
SRV2 VERBOSE 6/24/2016 11:36:56 AM [SRV2]: LCM: [ End Resource ] [[xDSCWebService]PSDSCP...
SRV2 VERBOSE 6/24/2016 11:36:56 AM [SRV2]: [] Consistency check co...
SRV2 ANALYTIC 6/24/2016 11:36:56 AM Deleting file from C:\Windows\System32\Configuration\DSCEngineCach...
SRV2 OPERATIONAL 6/24/2016 11:36:56 AM Consistency engine was run successfully.
SRV2 OPERATIONAL 6/24/2016 11:36:56 AM Job runs under the following LCM setting. ...
SRV2 OPERATIONAL 6/24/2016 11:36:56 AM Operation Consistency Check or Pull completed successfully.
SRV2 ANALYTIC 6/24/2016 11:36:56 AM Deleting file from C:\Windows\System32\Configuration\DSCEngineCach...
## My resources won’t update: How to reset the cache
The DSC engine caches resources implemented as a PowerShell module for efficiency purposes. However, this can cause problems when you are authoring a resource and testing it simultaneously because DSC will load the cached version until the process is restarted. The only way to make DSC load the newer version is to explicitly kill the process hosting the DSC engine.
Similarly, when you run `Start-DscConfiguration`, after adding and modifying a custom resource, the modification may not execute unless, or until, the computer is rebooted. This is because DSC runs in the WMI Provider Host Process (WmiPrvSE), and usually, there are many instances of WmiPrvSE running at once. When you reboot, the host process is restarted and the cache is cleared.
To successfully recycle the configuration and clear the cache without rebooting, you must stop and then restart the host process. This can be done on a per instance basis, whereby you identify the process, stop it, and restart it. Or, you can use `DebugMode`, as demonstrated below, to reload the PowerShell DSC resource.
To identify which process is hosting the DSC engine and stop it on a per instance basis, you can list the process ID of the WmiPrvSE which is hosting the DSC engine. Then, to update the provider, stop the WmiPrvSE process using the commands below, and then run **Start-DscConfiguration** again.
```powershell
###
### find the process that is hosting the DSC engine
###
$dscProcessID = Get-WmiObject msft_providers |
Where-Object {$_.provider -like 'dsccore'} |
Select-Object -ExpandProperty HostProcessIdentifier
###
### Stop the process
###
Get-Process -Id $dscProcessID | Stop-ProcessYou can configure the DSC Local Configuration Manager (LCM) to use DebugMode to always clear the cache when the host process is restarted. When set to TRUE, it causes the engine to always reload the PowerShell DSC resource. Once you are done writing your resource, you can set it back to FALSE and the engine will revert to its behavior of caching the modules.
Following is a demonstration to show how DebugMode can automatically refresh the cache. First, let’s look at the default configuration:
PS C:\> Get-DscLocalConfigurationManager
AllowModuleOverwrite : False
CertificateID :
ConfigurationID :
ConfigurationMode : ApplyAndMonitor
ConfigurationModeFrequencyMins : 30
Credential :
DebugMode : False
DownloadManagerCustomData :
DownloadManagerName :
LocalConfigurationManagerState : Ready
RebootNodeIfNeeded : False
RefreshFrequencyMins : 15
RefreshMode : PUSH
PSComputerName :
You can see that DebugMode is set to FALSE.
To set up the DebugMode demonstration, use the following PowerShell resource:
function Get-TargetResource
{
param
(
[Parameter(Mandatory)]
$onlyProperty
)
return @{onlyProperty = Get-Content -Path "$env:SystemDrive\OutputFromTestProviderDebugMode.txt"}
}
function Set-TargetResource
{
param
(
[Parameter(Mandatory)]
$onlyProperty
)
"1" | Out-File -PSPath "$env:SystemDrive\OutputFromTestProviderDebugMode.txt"
}
function Test-TargetResource
{
param
(
[Parameter(Mandatory)]
$onlyProperty
)
return $false
} Now, author a configuration using the above resource called TestProviderDebugMode:
Configuration ConfigTestDebugMode
{
Import-DscResource -Name TestProviderDebugMode
Node localhost
{
TestProviderDebugMode test
{
onlyProperty = "blah"
}
}
}
ConfigTestDebugModeYou will see that the contents of file: “$env:SystemDrive\OutputFromTestProviderDebugMode.txt” is 1.
Now, update the provider code using the following script:
$newResourceOutput = Get-Random -Minimum 5 -Maximum 30
$content = @"
function Get-TargetResource
{
param
(
[Parameter(Mandatory)]
`$onlyProperty
)
return @{onlyProperty = Get-Content -Path "$env:SystemDrive\OutputFromTestProviderDebugMode.txt"}
}
function Set-TargetResource
{
param
(
[Parameter(Mandatory)]
`$onlyProperty
)
"$newResourceOutput" | Out-File -PSPath C:\OutputFromTestProviderDebugMode.txt
}
function Test-TargetResource
{
param
(
[Parameter(Mandatory)]
`$onlyProperty
)
return `$false
}
"@ | Out-File -FilePath "C:\Program Files\WindowsPowerShell\Modules\MyPowerShellModules\DSCResources\TestProviderDebugMode\TestProviderDebugMode.psm1This script generates a random number and updates the provider code accordingly. With DebugMode set to false, the contents of the file “$env:SystemDrive\OutputFromTestProviderDebugMode.txt” are never changed.
Now, set DebugMode to TRUE in your configuration script:
LocalConfigurationManager
{
DebugMode = $true
} When you run the above script again, you will see that the content of the file is different every time. (You can run Get-DscConfiguration to check it). Below is the result of two additional runs (your results may be different when you run the script):
PS C:\> Get-DscConfiguration -CimSession (New-CimSession localhost)
onlyProperty PSComputerName
------------ --------------
20 localhost
PS C:\> Get-DscConfiguration -CimSession (New-CimSession localhost)
onlyProperty PSComputerName
------------ --------------
14 localhost