For x86/64 based systems with a monitor I’ve mostly been successful using gparted (CD or USB) and the dd command.
More recently I have been using pfSense VM’s on ESXi (Free). With Nakivo Backup (Free) you can backup 2 VM’s straight onto a Synology NAS (intel CPU only).
With open-vm-tools running inside the pfsense VM i can do automated full backups every night without the need to shut down . Since the backups are snapshot based they only take a few seconds. (The first backup takes a few minutes). Restores only take a few minutes, too and you can select a different Esxi host as target.
For the backups to work (esxi snapshots) you won’t be able to pass through phyisical NICs via vt-d, however i couldnt notice any performance impact using vmxnet3 adapters...