Creating Plans to Protect Data › How to Create a Host-Based Virtual Machine Backup Plan › Troubleshooting › Backup Job is Complete but the VM is in the Backing Up Status

Backup Job is Complete but the VM is in the Backing Up Status

Valid for Hyper-V VM

Symptom

In Hyper-V 2012 or later, the virtual machine stays in the Backing up status although the agent-less host-based backup job of this virtual machine has already finished. I cannot perform some operations such as power-on or power-off the virtual machine during that time in the Hyper-V manager. If the virtual machine is a Hyper-V cluster, I cannot perform live migration for it. In addition, if another backup job for this VM starts at the same time, the backup job fails with the following error:

The Hyper-V VSS writer has encountered an error when processing this virtual machine.

This problem occurs in the following situations:

• There are several backup jobs starting at the same time or at times closer to each other (within one minute).
• One or more backup jobs are complete, but there is still at least one backup job in progress.

Solution

If the backup jobs start at the same time or at times closer to each other, Arcserve UDP takes one VSS snapshot for all virtual machines instead of taking one VSS snapshot for each virtual machine. This avoids unnecessary workload to the Hyper-V host. After the VSS snapshot is taken, all the virtual machines inside this VSS snapshot instance are locked (in the Backing up status). Arcserve UDP cannot release the snapshot until all backup jobs are finished, even if the backup job of a virtual machine is already completed.

The VSS snapshot has a limitation. Only one snapshot can be taken for a virtual machine at a time. If another backup job of the same virtual machine starts at this time, it fails and provides the error message. This error does not happen in Hyper-V 2008R2 because Hyper-V 2008R2 has a different VSS snapshot mechanism.

While the virtual machine is locked, you can still use the guest OS. The lock has no impact on the usage or availability of the guest OS. However, to avoid this situation, you can perform either of the following tasks:

• Enable the Hyper-V Snapshot Separation option on the resource tab of the agent-less host-based backup. Then, Arcserve UDP takes a separate snapshot for each virtual machine specified in the plan. The virtual machine is released after the backup is complete.
• Use different plans to protect virtual machines that have different storage sizes. Include the virtual machines with similar storage size in one plan. It will ensure that the backup jobs take a similar amount of time to complete. Also, set different schedules different plans.