diff --git a/tools/g2/lib/virsh.sh b/tools/g2/lib/virsh.sh
index dc02a2b9..76d3a5d4 100644
--- a/tools/g2/lib/virsh.sh
+++ b/tools/g2/lib/virsh.sh
@@ -75,8 +75,10 @@ iso_path() {
 }
 
 net_clean() {
-    log net_clean is not yet implemented.
-    exit 1
+    if virsh net-list --name | grep ^promenade$ > /dev/null; then
+        log Destroying promenade network
+        virsh net-destroy "${XML_DIR}/network.xml" &>> "${LOG_FILE}"
+    fi
 }
 
 net_declare() {
@@ -120,6 +122,7 @@ vm_create() {
     vol_create_root "${NAME}"
 
     log Creating VM "${NAME}"
+    DISK_OPTS="bus=virtio,cache=directsync,discard=unmap,format=qcow2"
     virt-install \
         --name "${NAME}" \
         --virt-type kvm \
@@ -130,9 +133,9 @@ vm_create() {
         --vcpus "$(config_vm_vcpus)" \
         --memory "$(config_vm_memory)" \
         --import \
-        --disk "vol=${VIRSH_POOL}/promenade-${NAME}.img,format=qcow2,bus=virtio" \
-        --disk "pool=${VIRSH_POOL},size=20,format=qcow2,bus=virtio" \
-        --disk "pool=${VIRSH_POOL},size=20,format=qcow2,bus=virtio" \
+        --disk "vol=${VIRSH_POOL}/promenade-${NAME}.img,${DISK_OPTS}" \
+        --disk "pool=${VIRSH_POOL},size=20,${DISK_OPTS}" \
+        --disk "pool=${VIRSH_POOL},size=20,${DISK_OPTS}" \
         --disk "vol=${VIRSH_POOL}/cloud-init-${NAME}.iso,device=cdrom" &>> "${LOG_FILE}"
 
     ssh_wait "${NAME}"
diff --git a/tools/g2/stages/join-masters.sh b/tools/g2/stages/join-masters.sh
index 7ddd6eaf..e67d8043 100755
--- a/tools/g2/stages/join-masters.sh
+++ b/tools/g2/stages/join-masters.sh
@@ -16,6 +16,9 @@ for NAME in ${JOIN_TARGETS}; do
 
     ssh_cmd "${NAME}" "/root/promenade/join-${NAME}.sh"
     ssh_cmd "${NAME}" "/root/promenade/validate-${NAME}.sh"
+
+    # NOTE(mark-burnett): Ensure disk cache is flushed after join.
+    ssh_cmd "${NAME}" sync
 done
 
 validate_cluster n0
diff --git a/tools/g2/stages/reprovision-genesis.sh b/tools/g2/stages/reprovision-genesis.sh
index 123fd697..6a865053 100755
--- a/tools/g2/stages/reprovision-genesis.sh
+++ b/tools/g2/stages/reprovision-genesis.sh
@@ -20,3 +20,6 @@ validate_cluster n1
 
 validate_etcd_membership kubernetes n1 "${EXPECTED_MEMBERS}"
 validate_etcd_membership calico n1 "${EXPECTED_MEMBERS}"
+
+# NOTE(mark-burnett): Ensure disk cache is flushed after join.
+ssh_cmd "${GENESIS_NAME}" sync
diff --git a/tools/stop_gate.sh b/tools/stop_gate.sh
index 94ae4edf..e4d299a9 100755
--- a/tools/stop_gate.sh
+++ b/tools/stop_gate.sh
@@ -12,4 +12,5 @@ export WORKSPACE
 source "${GATE_UTILS}"
 
 vm_clean_all
+net_clean
 registry_down