Hyper-V Settings

To specify Hyper-V settings for the replication job:

1. At the Job Settings step of the wizard, click Advanced.
2. In the Advanced Settings window, click the Hyper-V tab.
3. In the Guest quiescence section, do the following:

1. If VMs added to the replication job do not support Microsoft VSS framework or you want to use native Microsoft Hyper-V method for guest quiescence, select the Enable Hyper-V guest quiescence check box.

Veeam Backup & Replication will select the quiescence method in the following way:

• If a VM meets all requirements for online backup, Veeam Backup & Replication will use the online backup method. For more information on the method, its requirements and limitations, see Online Backup.
• If a VM does not meet requirements for online backup, Veeam Backup & Replication will use the offline backup method. Note that during offline backup a VM is suspended for a short period of time. For more information the method, its requirements and limitations, see Offline Backup.

2. If you do not want to suspend VMs, select the Take crash consistent backup instead of suspending VM check box. In this case, Veeam Backup & Replication will create crash-consistent VM replicas.

4. In the Changed block tracking section, specify if you want to use changed block tracking (CBT) for VM replication. For more information on CBT, see Changed Block Tracking.
5. If you have added several VMs to the job, select the Allow processing of multiple VMs with a single volume snapshot check box. This option helps reduce snapshot workload in the Microsoft Hyper-V environment. When the job starts, Veeam Backup & Replication will group VMs and trigger Microsoft Hyper-V to create one volume snapshot for a group of VMs, instead of creating a volume snapshot per each processed VM.

Veeam Backup & Replication can create a single volume snapshot for a group of VMs that meet the following requirements:

• VMs must be located on the same host.
• Volumes on which VM files reside must use the same VSS provider for snapshot creation.
• The number of VMs in the group is limited: for VSS software provider — 4 VMs, for VSS hardware provider — 8 VMs.
• Veeam Backup & Replication groups VMs based on the method of snapshot creation that is used for replication: transactionally consistent (VSS) or crash-consistent.

For example, you add to the job two VMs that are registered on the same host. VM1 resides on volume C:\ and VM2 resides on volume D:\. Both VMs use Microsoft Software Shadow Copy Provider. In this situation, Veeam Backup & Replication will create a single snapshot for these VMs.

6. If you want to save this set of settings as the default one, click Save as default. When you create a new job, the saved settings will be offered as the default. This also applies to all users added to the backup server.