Backup of a virtual guest fails intermittently generating a IRPSTACKSIZE windows event.

  • Article ID:100011648
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Backing up a Windows 2003 or earlier virtual guest system using either the Agent for Hyper-V systems or Agent for VMWare Virtual Infrastructure intermittently fails with the error and Windows event message below.

Error Message

Error E7D1001E: Unable to read from file.

Error 0000046A: Not enough server storage is available to process this command"


Event Viewer Error:

Event ID: 2011

Description: The server's configuration parameter "irpstacksize" is too small for the server to use a local device. Please increase the value of this parameter.



  1. This is caused by an IRP stack size which is too small for the current operation.
  2. In some cases it may be related to the drive on which the backup is being created.
  3. Is known to happen on some external USB hard disks, when backing up to the drive over SAN, NAS, network share, or any other backup destination over the network.
  4. Antivirus software may cause Event ID 2011 as well.




Check each of the following:
1. Verify exceptions has been made within your Antivirus software for Backup Exec. For more information about how Antivirus software may cause Event ID 2011 review:
2. Attempt to backup to a different storage media for select virtual guest systems that has a higher then normal rate of backup failure, if the problem persist, check both the file system integrity of the virtual guest disks using a utility like CHKDSK and fragmentation level. In some cases moving the *.VHD or *.VMDK files composing this virtual guest to a different data store has resolved this issue.
3. Increase the IRPSTACKSIZE value on both the media server and virtualized guest being backed up by following the steps listed below:
Warning: Incorrect use of the Windows registry editor may prevent the operating system from functioning properly. Great care should be taken when making changes to a Windows registry. Registry modifications should only be carried-out by persons experienced in the use of the registry editor application. It is recommended that a complete backup of the registry and workstation be made prior to making any registry changes.

1. Click Start, and then click Run.

2. Type regedit, and then click OK.

3. Navigate to the following registry key:
4. In the right pane, double-click the IRPStackSize value.
     If the IRPStackSize value does not already exist, it has to be created:
         a.  In the Parameters folder of the registry, right-click the right pane.
         b.  Point to New, and then click DWord Value.
         c.  Type "IRPStackSize" It is important to type this exactly as it appears, the registry is case-sensitive.
5. Change the Base to decimal.
6. In the Value Data box, type a value that is larger than the value that is listed.
    If you had created the IRPStackSize value using the procedure described in step 4, the default value is 15 or 18 depending on OS version (15 in Windows 2000, 18 in Windows 2003). It is recommended that you increase the value by 3. Therefore, if the previous value was 11, type 14, and then click OK.
7. Close the Registry Editor.
8. Restart the computer.
For additional information about the IRP Stacksize, please review the following Microsoft Knowledgebase Article:
Description of the IRPStackSize parameter in Windows 2000, in Windows XP, and in Windows Server 2003


Applies To

Windows 2003 or earlier virtual guest systems

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