Use apt-get -t instead of preferences to install newer qemu-kvm

etc/apt/preferences

@@ -1,7 +1,3 @@
 Package: *
 Pin: release a=unstable
 Pin-Priority: 50
-
-Package: qemu* ipxe-qemu libgf* libgluster*
-Pin: release a=unstable
-Pin-Priority: 500

opennebula.sh

@@ -33,9 +33,13 @@ apt-get update || true
 
 DEBIAN_FRONTEND=noninteractive apt-get -o Dpkg::Options::="--force-confdef" \
     -o Dpkg::Options::="--force-confold" install -y \
-    lsb-release keepalived sudo qemu qemu-kvm qemu-block-extra mariadb-server netcat-openbsd \
+    lsb-release keepalived sudo mariadb-server netcat-openbsd \
     opennebula opennebula-sunstone opennebula-gate opennebula-flow opennebula-node opennebula-tools ceph
 
+DEBIAN_FRONTEND=noninteractive apt-get -o Dpkg::Options::="--force-confdef" \
+    -o Dpkg::Options::="--force-confold" install -y -t sid \
+    qemu qemu-kvm qemu-block-extra
+
 /usr/share/one/install_gems --yes
 EOF