Troubleshooting SCVMM: Resolving HostAgentFail (2912) Errors Effectively

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This document addresses a common issue encountered in System Center Virtual Machine Manager (SCVMM): the HostAgentFail (2912) error. This error typically arises when any SCVMM operation involving data transfer, such as copying virtual hard disk files (.vhd, .vhdx) or ISO images, fails. Understanding the symptoms, causes, and effective resolutions is crucial for maintaining a healthy and efficient virtualized environment. This guide provides a comprehensive approach to diagnosing and resolving HostAgentFail (2912) errors, ensuring smooth operation of your SCVMM infrastructure.

Symptoms¶

The primary indicator of this problem is the failure of any SCVMM activity that necessitates moving data. This often manifests during operations like virtual machine migration, storage migration, or even template deployment when large files are involved. The error typically surfaces early in the data transfer process, halting the operation shortly after it begins. Users will observe job failures in the SCVMM console with the specific error code HostAgentFail (2912).

Delving deeper into the SCVMM trace logs provides more granular details. A typical log snippet reveals that the Background Intelligent Transfer Service (BITS) is initiated for the data transfer. Examining the error stack in the logs, you will usually find the exception HostAgentFail (2912); HR: 0x80041001 at the bottom. Preceding this exception, events leading up to the failure indicate BITS attempting to start a copy job, as shown in the log excerpt: at Microsoft.VirtualManager.Engine.Deployment.BitDeployer.Copy().

The detailed error message in the trace typically includes a WSManProviderException, highlighting communication issues with the agent on the target server. It often suggests verifying agent installation and WS-Management service status. However, in the context of HostAgentFail (2912) related to suspended BITS jobs, these standard agent checks might not directly pinpoint the root cause. The core issue lies not necessarily in agent connectivity itself, but in BITS job management.

The following is an example of a VMM trace snippet illustrating the error:

timedate,0x09C4,0x0994,4,BitsDeployer.cs,506,0x00000000, Caught Exception,{00000000-0000-0000-0000-000000000000},1,<br>
timedate,0x09C4,0x0994,4,BitsDeployer.cs,506,0x00000000,"Microsoft.Carmine.WSManWrappers.WSManProviderException: An internal error has occurred trying to contact an agent on the Server.Domain.com server.<br>
17993 Ensure the agent is installed and running. Ensure the WS-Management service is installed and running; then restart the agent.<br>
at Microsoft.Carmine.WSManWrappers.ErrorContextParameterHelper.ThrowTranslatedCarmineException(ErrorInfo ei; Exception ex)<br>
at Microsoft.Carmine.WSManWrappers.WsmanAPIWrapper.RetrieveUnderlyingWMIErrorAndThrow(SessionCacheElement sessionElement; COMException ce)<br>
at Microsoft.Carmine.WSManWrappers.WsmanAPIWrapper.Enumerate(String url; String filter; Type type)<br>
at Microsoft.Carmine.WSManWrappers.WSManRequest`1.Enumerate(String url; String wqlQuery)<br>
at Microsoft.VirtualManager.Engine.Deployment.NativeDeploymentUtils.IsBitsRemoteApiAvailable(WSManConnectionParameters connectionParams; BitsRemoteApi remoteApi)<br>
at Microsoft.VirtualManager.Engine.Deployment.LANAcceleratorFactory.GetDeploymentClientJob(WSManConnectionParameters connParams; WSManConnectionParameters remotePeerConnParams; String sourceFileName; String targetFilename; UInt16 port; Boolean privacy; UInt32 flags; String sessionID; Boolean resetJob)<br>
at Microsoft.VirtualManager.Engine.Deployment.BITSDeployer.CreateClientJob(DeploymentFile file; CLIENT_JOB_TYPE clientJobType; WSManConnectionParameters clientConnection; WSManConnectionParameters serverConnection; UInt16 serverTcpPort; Boolean clientPrivacy; Boolean startAfresh)<br>
at Microsoft.VirtualManager.Engine.Deployment.BitDeployer.Copy()<br>
*** Carmine error was: HostAgentFail (2912); HR: 0x80041001

This log excerpt clearly demonstrates the sequence of events leading to the HostAgentFail error, starting with BITS job initiation and culminating in the exception. Analyzing such logs is vital for accurate diagnosis.

Cause¶

The root cause of the HostAgentFail (2912) error in these scenarios is often related to suspended BITS jobs. BITS, a Windows service used for asynchronous file transfers, can sometimes leave jobs in a suspended state. These suspended jobs can originate from various sources, including previous failed SCVMM operations, Windows Updates, software installations, or other applications utilizing BITS for data transfer.

When BITS has a job suspended on either the VMM server itself or the host machine involved in the data transfer, it can prevent new BITS jobs from starting. SCVMM relies on BITS for many data movement tasks. If BITS is blocked due to existing suspended jobs, SCVMM operations that require data transfer will fail, resulting in the HostAgentFail (2912) error. Effectively, the error is not necessarily a direct failure of the agent itself, but rather a consequence of BITS being unable to function correctly due to job congestion.

Imagine BITS as a highway for data transfer. If there’s a stalled vehicle (a suspended job) blocking a lane, new traffic (SCVMM data transfer jobs) cannot proceed smoothly. Clearing the stalled vehicle (removing the suspended BITS job) is necessary to restore traffic flow and allow new operations to proceed. Therefore, resolving the HostAgentFail (2912) error in this context primarily involves identifying and clearing these suspended BITS jobs.

Resolution¶

Resolving the HostAgentFail (2912) error caused by suspended BITS jobs requires a straightforward procedure involving the command-line tool bitsadmin. This process needs to be performed on both the SCVMM server and any host servers involved in the failed data transfer operation. This ensures that suspended BITS jobs are cleared from all relevant machines.

Here are the step-by-step instructions to resolve this issue:

1. Open an Elevated Command Prompt: On both the SCVMM server and the affected host servers, open a command prompt with administrator privileges. This is crucial as bitsadmin operations often require elevated permissions to manage BITS jobs system-wide. You can do this by searching for “cmd” in the Start menu, right-clicking on “Command Prompt,” and selecting “Run as administrator.”

2. List All BITS Jobs: In the elevated command prompt, execute the following command and press Enter:

   bitsadmin /list /allusers
   

   This command instructs bitsadmin to list all BITS jobs currently active on the system, including those owned by all users. The output will display a table format, providing details about each job, such as the job name, owner, state, and progress.

3. Identify Suspended Jobs: Carefully examine the output of the bitsadmin /list /allusers command. Look for jobs that are in a “SUSPENDED” state. Each BITS job is uniquely identified by a GUID (Globally Unique Identifier), which appears at the beginning of each job entry in the list. Note down the GUIDs of all suspended jobs.

   A table can help visualize the output and quickly identify suspended jobs:

   Job GUID	Owner	State	Progress	…
   {xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx}	SYSTEM	TRANSFERRED	100%	…
   {yyyyyyyy-yyyy-yyyy-yyyy-yyyyyyyyyyyy}	Domain\User	SUSPENDED	50%	…
   {zzzzzzzz-zzzz-zzzz-zzzz-zzzzzzzzzzzz}	NETWORK SERVICE	ERROR	0%	…

   In this example, the second job with GUID {yyyyyyyy-yyyy-yyyy-yyyy-yyyyyyyyyyyy} is in a “SUSPENDED” state and needs to be cancelled.

4. Cancel Suspended Jobs: For each suspended job identified in the previous step, use the bitsadmin /cancel command to cancel it. The command syntax is as follows:

   bitsadmin /cancel {GUID}
   

   Replace {GUID} with the actual GUID of the suspended BITS job you noted down. For example, if a suspended job has the GUID {yyyyyyyy-yyyy-yyyy-yyyy-yyyyyyyyyyyy}, the command would be:

   bitsadmin /cancel {yyyyyyyy-yyyy-yyyy-yyyy-yyyyyyyyyyyy}
   

   Execute this command for each suspended job you identified. bitsadmin will attempt to cancel the specified job.

5. Repeat for All Suspended Jobs: Repeat step 4 for every suspended BITS job listed in the output of the bitsadmin /list /allusers command. Ensure that you cancel all suspended jobs to clear any potential blockage for new BITS operations.

6. Verify No More Suspended Jobs: After cancelling all identified suspended jobs, it’s good practice to re-run the bitsadmin /list /allusers command one more time:

   bitsadmin /list /allusers
   

   Review the output again to confirm that there are no more jobs in a “SUSPENDED” state. This ensures that you have successfully cleared all problematic BITS jobs. Ideally, after cancelling the suspended jobs, the list should either be empty or contain only jobs in other states like “TRANSFERRED” or “ERROR” that are not actively hindering new operations.

By following these steps on both the SCVMM server and relevant host machines, you should effectively resolve the HostAgentFail (2912) error caused by suspended BITS jobs. After clearing these jobs, retry the failed SCVMM operation. It should now proceed without the HostAgentFail (2912) error.

More Information¶

It’s important to understand that BITS is a system-level service utilized by various applications in Windows, not just SCVMM. Windows Update, software installers (like Java Updates), and many other applications rely on BITS for background data transfers. Therefore, suspended BITS jobs can originate from a wide range of sources, not solely from SCVMM actions.

While suspended BITS jobs can be triggered by previous failed SCVMM operations, they can also be caused by unrelated software activities or system events. Network interruptions, system restarts during data transfers, or software conflicts can all potentially lead to BITS jobs becoming suspended. Regularly checking for and clearing suspended BITS jobs, especially on servers involved in critical operations like SCVMM management, can proactively prevent HostAgentFail (2912) errors and ensure smoother system performance.

Furthermore, consider implementing monitoring for BITS job states on your SCVMM servers and hosts. Proactive monitoring can alert you to the presence of suspended jobs before they impact critical SCVMM operations, allowing for timely intervention and preventing disruptions. This could involve scripting or using system monitoring tools to periodically check BITS job status and trigger alerts based on predefined thresholds.

By understanding the role of BITS in data transfer, recognizing the symptoms and causes of HostAgentFail (2912) errors related to suspended BITS jobs, and implementing the resolution steps outlined in this guide, administrators can effectively troubleshoot and prevent this common SCVMM issue, maintaining a stable and efficient virtualized infrastructure.

If the issue persists even after clearing suspended BITS jobs, further investigation into network connectivity, agent health, and other potential underlying problems might be necessary. However, for many instances of HostAgentFail (2912) errors in SCVMM data transfer operations, resolving suspended BITS jobs provides a direct and effective solution.

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Have you encountered HostAgentFail (2912) errors in your SCVMM environment? Share your experiences and any additional troubleshooting tips in the comments below!