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

Article:TECH209119  |  Created: 2013-07-29  |  Updated: 2013-10-02  |  Article URL
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.





Increase the number of fragments that can be kept open at a time.

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.  Browse to HKLM\Software\Symantec\PureDisk\PDVFS

2.  Create a DWORD value named "MaxOpenFragments" and set the value to 22 (decimal).

3.  Stop and Start the PDVFS and Backup Exec services in that order.


If with the above setting the freeze/hang still occurs turn off GRT for the VMware backups. Do remote agent backups to maintain GRT restore capability.

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.

Supplemental Materials


Manage Media Server lost Communications and became unresponsive


Backup server hangs while performing AVVI backups

Article URL

Terms of use for this information are found in Legal Notices