How to troubleshoot backup or restore jobs that complete with an error or exception "Failed to mount one or more virtual disk images" when protecting Virtual Machines stored within VMware ESX 3.5:

Article:TECH63607  |  Created: 2009-01-28  |  Updated: 2014-04-28  |  Article URL http://www.symantec.com/docs/TECH63607
Article Type
Technical Solution


Issue



How to troubleshoot backup or restore jobs that complete with the following error or exception when protecting Virtual Machines stored within VMware ESX 3.5:


Error



Failed to mount one or more virtual disk images


Cause



Backups

Note: The following steps only apply to Backup Exec 12.5.
Backup Exec 2010 and higher no longer uses the VMware Consolidated Backup proxy. It is recommend to upgrade to Backup Exec 2010 or higher to backup VMware using the vStorage APIs.

 

Several configurations can cause the above error.  Please review the possible causes below, and reference the matching solution.

1.  Backing up the same virtual machine running concurrently to the same temporary staging location.

2.  The VMware Consolidated Backup (VCB) is not installed.

3.  The VMware Consolidated Backup is not targeted correctly in the backup job properties.

All of these scenarios when using the Agent for VMware Virtual Infrastructure will cause the job to report the error or exception "V-79-57344-38721 - Failed to mount one or more virtual disk images". The GRT (Granular Restore Technology) functionality will fail for this backup, and individual file restores will not be possible as the VMware Consolidated Backup (VCB) is not able to mount the image file.
 

Restore

 

Backup Exec 2010 and above Agent for VMware now fully incorporates the VMware vStorage API's for Data Protection (requires ESX 3.5 U2 or higher). VMware's Consolidated Backup (VCB) infrastructure is no longer required to be used or installed for backups of ESX Update 2 and later. However, to restore Backup Exec 12.5 backups, VCB. 1.5 is required to be installed in order to restore older backup sets created with VCB.


Solution



Backup Exec 12.5

1. Avoid conflicts of the scheduled jobs so that they do not overlap while taking backup of the same virtual machine.

2. Install the VMware Consolidated Backup  http://www.vmware.com/download/vi/drivers_tools.html

3.  Verify the location where VMware Consolidated Backup is installed, in comparison with the location specified in the backup job properties.

If the issue still occurs after performing the steps mentioned above, review the TechNotes in the Related Documents Section below.
 

Supplemental Materials

SourceUMI
ValueV-79-57344-38721
Description

Failed to mount one or more virtual disk images



Legacy ID



308944


Article URL http://www.symantec.com/docs/TECH63607


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