I've covered this before, but this time we're not using VBoxManage import/export but will clone the disk, then create a new VM:

$ mkdir vm1
$ VBoxManage clonehd vm0/disk0.vdi vm1/disk0.vdi

$ VBoxManage createvm --ostype Debian_64 --name vm1 --basefolder `pwd` --register
Virtual machine 'vm1' is created and registered.
UUID: f9f52566-40df-48cd-bb5f-c52e6d050260
Settings file: 'vm1/vm1.vbox'

Now the VM and its disk is already in place, we're going to tune our VM a bit and attach the disk to the VM:

$ VBoxManage modifyvm vm1 --memory 256 --rtcuseutc on --pae off \
                      --boot1 disk --boot2 dvd --boot3 none --boot4 none \
                      --nic1 bridged --nictype1 virtio --bridgeadapter1 "en1"

$ VBoxManage storagectl vm1 --name "SATA Controller" --add sata \
                      --controller IntelAHCI --sataportcount 1

$ VBoxManage storageattach vm1 --storagectl "SATA Controller" \
                      --port 0 --device 0 --type hdd --medium `pwd`/vm1/disk0.vdi

:-)