Backup server hangs while performing GRT based AVVI backups of Virtual Machines to a Deduplication Folder.

Article:TECH209119  |  Created: 2013-07-29  |  Updated: 2014-10-21  |  Article URL
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Article Type
Technical Solution


Backup server goes in to a hang (freeze) while performing Granular Recovery Technology (GRT) based AVVI  backups of Virtual Machines to a Deduplication Folder


This problem can occur while backing up larger Virtual Machines (around and above 1TB). The problem comes from the repeated open/close calls using PDVFS (Pure Disk Virtual File System Service) that has to be made when reading the large size VMDK's.




Backup Exec 2014 Service Pack1 allows to implement a workaround for this issue. After updating the Backup Exec 2014 server to SP1, please execute 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)   On the Backup Exec server, enable the following registry value (Use VMDK Remote Mount =1):

      Key location:  HKEY_LOCAL_MACHINE\SOFTWARE\Symantec\Backup Exec For Windows\Backup Exec\Engine\VMware Agent 

      DWORD value:  Use VMDK Remote Mount

      Set the value to 1.

2)   Create or edit the existing backup job for the VMWare guest machines to DISABLE the Delayed Catalog  feature.  In the edit job options, under ‘Delayed Catalog’ tab, choose ‘Do not run a delayed catalog operation’.


NOTE:  A GRT related warning will be displayed in the backup sets for Virtual Machines (figure 1) if delayed catalog setting was NOT disabled after creating the above mentioned registry value, however this will not have any impact on GRT restores from the backup set.

Figure 1:


Symantec Corporation has acknowledged that the above-mentioned issue is present in the current version(s) of the product(s) mentioned at the end of this article. Symantec Corporation is committed to product quality and satisfied customers.

This issue is currently under investigation by Symantec Corporation. Pending the outcome of the investigation, this issue may be resolved by way of a patch or hotfix in current or future revisions of the software. However, this particular issue is not currently scheduled for any release.  If you feel this issue has a direct business impact for you and your continued use of the product, please contact your Symantec Sales representative or the Symantec Sales group to discuss these concerns.  For information on how to contact Symantec Sales, please see Please be sure to refer back to this document periodically as any changes to the status of the issue will be reflected here.

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Backup server hangs while performing AVVI backups

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