For Hyper-V Snapshot (Shadow Copy) Failures

  • Export the following event logs from the standalone Hyper-V host or from all cluster nodes:
    • Windows Logs > System
    • Windows Logs > Application
    • Applications and Services Logs>Microsoft>Hyper-V-VMMS>Admin
      User-added image
  • If Application-Aware Image Processing is enabled in the Backup or Replication job settings, test whether the failure occurs with that setting disabled.
  • If the problem occurs only when Application-Aware is enabled, export the Hyper-V-Integration log from the Hyper-V host managing the VM, then see Guest Processing Issues below.
    Note: For Hyper-V 2016 or newer this step can be skipped, as this section was removed in Server 2016.
    • Applications and Services Logs>Microsoft>Hyper-V-Integration>Admin
      User-added image


  • For Guest Processing Issues


  • Common examples include failure to truncate Exchange or SQL transaction logs, “VSSControl” error codes, and unexpected behavior occurring with the VM guest OS during backup.
  • Export these logs from the affected VM guest OS:
    • Windows Logs > System
    • Windows Logs > Application
  • You will typically also want to collect the Veeam VSS logs from the VM – see KB1789.


For Problems with Backup Infrastructure Servers

  • In all scenarios below, export the following from the appropriate server. When in doubt, export from the Veeam Backup server:
    • Windows Logs > System
    • Windows Logs > Application
  • If the error message is:
    • "task failed unexpectedly” - Export events from the Veeam Backup server.
    • referring to backup files on a Windows server - Export events from the repository server.
    • referring to backup files on a CIFS/SMB share - Export events from the gateway server, or from the Veeam Backup server and all proxies if no gateway was specified in the repository settings.