Backup and Replication jobs fail with the following error: "CDeviceBase: resize is not supported. Failed to download disk".
The following conditions must be met:
- Veeam 8 Update 2 [18.104.22.1681] or later
- Backed up VM is running on ESXi 5.5 or later
- Hot Add transport mode is used
- VM has virtual disks with the same names attached to different SCSI controllers at the same device number, e.g. SCSI(0:0)=myVM.vmdk and SCSI(1:0)=myVM.vmdk
In certain circumstances, such as when provisioned virtual disk sizes of all disks are the same, or depending on hot add sequence of attaching virtual disks, this VDDK bug can cause the job reporting success while creating an unrecoverable backup, where each backed up virtual disk includes data from the last virtual disk that was hot added.