Application-Aware Processing

To create transactionally consistent backups or replicas of VMs that run Microsoft Active Directory, Microsoft SQL Server, Microsoft SharePoint, Microsoft Exchange or Oracle, you must enable application-aware processing in job settings.

Application-aware processing is the Veeam technology based on Microsoft VSS. Microsoft VSS is responsible for quiescing applications on the VM and creating a consistent view of application data on the VM guest OS. Use of Microsoft VSS ensures that there are no unfinished database transactions or incomplete application files when Veeam Backup & Replication triggers the VM snapshot and starts copying VM data to the target. For more information about Microsoft VSS, see Microsoft Docs.

Application-aware processing is supported for Microsoft Windows client versions starting from Windows Vista and for server versions starting from Windows Server 2008. To use application-aware processing, you must have VMware Tools and the latest updates installed on the VM guest OS.

Application-Aware ProcessingImportant!

If a VM runs an application that does not support Microsoft VSS (there is no VSS writer for this particular type of application, for example, MySQL), Veeam Backup & Replication will not be able to utilize Microsoft VSS and application-aware processing for this VM. To process such VMs, you can use VMware Tools quiescence with pre-freeze and post-thaw scripts. For more information, see VMware Tools Quiescence and Pre-Freeze and Post-Thaw Scripts.

How Application-Aware Processing Works

If you enable application-aware processing in job settings, Veeam Backup & Replication performs the following operations as a part of the backup or replication process:

  1. Veeam Backup & Replication deploys the non-persistent runtime components or, if necessary, persistent agent components on the VM and detects if the VM runs any of the supported applications.
  2. Veeam Backup & Replication collects information about applications installed on VMs — this information is required for VSS-aware restore.

VSS-aware restore is performed when the VM is started after you restore it from the backup or fail over to a VM replica.

  1. Veeam Backup & Replication prepares applications for VSS-aware restore.
  2. Microsoft VSS communicates with applications and quiesces I/O activities at a specific point in time.
  3. Veeam Backup & Replication acts as a VSS requestor and triggers a VM VSS snapshot.
  4. Veeam Backup & Replication triggers a VMware vSphere snapshot of the VM.
  5. Microsoft VSS resumes quiesced I/O activities on the VM guest OS.
  6. The job session proceeds as usual.
  7. If you have instructed Veeam Backup & Replication to truncate transaction logs, Veeam Backup & Replication truncates transaction logs on the VM guest OS after the backup or replica are successfully created.

Application-Aware Processing 

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