[root@kvm ~]# virsh domblklist zimbra --details
Tipo       Dispositivo Alvo       Fonte
------------------------------------------------
file       disk       vda        /var/lib/libvirt/images/zimbra.qcow2
file       cdrom      hda        -

[root@kvm images]# qemu-img create -f qcow2 /var/lib/libvirt/images/vdb-zimbra.img 50G
Formatting '/var/lib/libvirt/images/vdb-zimbra.img', fmt=qcow2 size=53687091200 encryption=off cluster_size=65536 lazy_refcounts=off

[root@kvm images]# virsh attach-disk zimbra /var/lib/libvirt/images/vdb-zimbra.img vdb --driver qemu --subdriver qcow2 --targetbus virtio --persistent
Disco conectado com sucesso

[root@kvm images]# virsh domblklist zimbra --details
Tipo       Dispositivo Alvo       Fonte
------------------------------------------------
file       disk       vda        /var/lib/libvirt/images/zimbra.qcow2
file       disk       vdb        /var/lib/libvirt/images/vdb-zimbra.img
file       cdrom      hda        -