Troubleshooting Checkpoint Creation Errors in KVM Environment

Troubleshooting Checkpoint Creation Errors in KVM Environment

KB ID: 221004
Cause:
The KB article focuses on problems that occur specifically within the KVM hypervisor environment during the creation of a checkpoint for a virtual machine. These errors can disrupt normal operations and may signify underlying issues. The article delves into the identified problem and offers corresponding solutions related to checkpoint creation.
Problem 1: Error with the message : "Operation not supported: incremental backup is not supported yet"
Solution 1: Enabling Incremental Backup Support
1. Launch the Virtual Machine Manager on your Linux system.
2. Navigate to "Edit" -> "Preferences" -> "General" within the Virtual Machine Manager.
3. Enable "XML Editing" in General preferences for configuration adjustments. Alternatively, directly edit the configuration file using `virsh edit <vm>`.
4. Access the summary page of the specific VM requiring incremental backup support.
5. Locate and navigate to the XML section within the summary page.
6. Copy the provided XML text:    
<domain type='kvm' xmlns:qemu='http://libvirt.org/schemas/domain/qemu/1.0'>
  [..]
<devices>
   [..]
   <qemu:capabilities>
       <qemu:add capability='incremental-backup'/>
   </qemu:capabilities>
</domain>
7. Paste the XML into the appropriate location in the XML configuration file and save.
Problem 2: Error with the message: "Unable to execute QEMU command 'transaction': Can't make bitmap 'BDRCheckpoint_[timestamp]' persistent in '[ID]': Cannot store dirty bitmaps in qcow2 v2 files"
Solution 2: Converting VM Disk from qcow2 v2 to v3
1. Ensure the VM is shut down for the conversion process.
2. Access the directory containing the VM disk.
3. Preserve the original disk file by renaming it:
mv disk0.qcow2 disk0_ori.qcow2
4. Execute the conversion command using qemu-img:
qemu-img convert -f qcow2 -O qcow2 -o compat=1.1 disk0_ori.qcow2 disk0.qcow2
5. Allow the conversion process to finish.
6. Power on the VM once the conversion is complete.
7. Optionally, delete the original disk file if no longer needed:
rm disk0_ori.qcow2
Note:  Restart the virtual machine after enabling this feature to ensure that the changes take effect.
Conclusion:
The outlined steps effectively enable incremental backup support and convert the VM disk format from qcow2 v2 to v3, effectively resolving their respective issues within the KVM hypervisor environment. By following these procedures, users ensure compatibility, optimize disk performance, and address encountered errors. For additional assistance, please contact BDRSuite Support at vembu-support@vembu.com.