Acronis Backup for VMware (Acronis vmProtect) has two ways recovering the virtual machines: to the origianl VM and to the new one. If the recovery is performed to the original location, Acronis software tries to locate the source VM using its GUID and if the VM is missing, the new VM will be created.
Recovering to original VM
In case the original VM exists, the software uses the following algorithm:
- When the recovery operation is started Acronis software powers off and creates the quiescied snapshot of the target VM using VMware API. This technical snapshot is required to be able to rollback in case the recovery operation fails.
- After the snapshot is created Acronis software mounts virtual disks to the Virtual Appliance and recovers data to existing disks. If Windows Agent is used or the Hot-Add functionality is not available, recovery is performed via network directly to the target VM.
- After data is recovered the software disconnects the virtual disks from Virtual Appliance and sends command to remove the technical snapshot created in the first step.
- And only after all these steps are performed the target VM is started.
In this situation if the restore operation fails then the software will rollback using to the snapshot that was created on the first step.
Recovering to a new VM
If the original VM is missing or the option to recover to a new VM is chosen the following algorithm is used:
- Acronis software sends the command to create a virtual machine on the VMware ESXi host where the recovery is performed
- After the VM is created Acronis software mounts the virtual disks to the Virtual Appliance and recovers the data to existing disks. If Windows Agent is used or the Hot-Add functionality is not available then the recover is performed via the network directly to target VM.
- After the recovery is finished, the disks are disconnected and the VM is started.
The difference between these algorithms is that the snapshot creation is not required in case if new VM is created. Besides that if the recovery is performed to existing VM then the vmFlashBack feature can be used during recovery.