Specifications

1.
2.
3.
vss writer error.
Resolving "Error Reading Object" Error During ESX or ESXi Virtual Machine
Backup
This article refers to all Barracuda Backup firmware 5.0 and higher, and VMware 4.0 and above with the VMware
®
license which
includes access to vSphere
®
Data Recovery API .
Additional Resource
VMware knowledgebase: QueryChangedDiskAreas API
call returns a FileFault error (2035976)
This article describes how to resolve the error "Error reading object" encountered while backing up an ESX/ESXi virtual machine. The most
common causes for this error are a crashed virtual machine or missing blocks on the virtual machine. When an error is encountered when backup
up the disk, the following displays in the vSphere logs:
Error QueryChangedDiskAreas
If you receive this error:
Use the following steps to resolve this error:
Remove all virtual machine snapshots.
Disable .changed block tracking
Enable changed block tracking.
Resolving "Error Removing Snapshot" Error During ESX/ESXi Virtual Machine
Backup
This article refers to Barracuda Backup firmware version 3.0 and higher, VMware 4.0 and above, VMware vCenter, vSphere , and
® ®
ESX, and Agent for VMware Virtual Infrastructure (AVVI).
When AVVI is enabled, you cannot manually delete a vCenter snapshot because when a snapshot is removed from a virtual machine, ESX
automatically creates a Consolidated Helper-0 snapshot which holds the snapshot data until the actual snapshot is deleted. Once the process is
complete, the Consolidated Helper-0 is rolled into the resulting file only when the following conditions are met:.vmdk
Consolidated Helper-0 snapshot file size must meet the minimal snapshot size in VMware which is less than 16MB
None or minimal I/O write on the virtual machine
To automatically delete a vCenter snapshots, log into the Barracuda Backup web interface, and go to the page.BACKUP > Schedules
If you attempt to manually delete a vCenter snapshot from Barracuda Backup before the Consolidated Helper-0 snapshot is rolled into the VMDK,
an error displays in the report page in the Barracuda Backup web interface, as shown in the following image:REPORTS > Backup
Additional Information
For more information, refer to the following VMware knowledgebase articles:
(1028924)VMware Data Recovery backup fails with the error: Failed to create snapshot. Error -3941
Cannot create a quiesced snapshot because the snapshot operation exceeded the time limit for
holding off I/O in the frozen virtual machine (1018194)
Contact for information on enabling CBT from the VMware API.Barracuda Networks Technical Support