vagrant-libvirt uses NFS to mount external directories

Change-Id: I3a731116049945b2fbf293d635873264b40f36d0
diff --git a/scripts/cord-in-a-box.sh b/scripts/cord-in-a-box.sh
index 4c4a026..d645b0c 100755
--- a/scripts/cord-in-a-box.sh
+++ b/scripts/cord-in-a-box.sh
@@ -57,7 +57,7 @@
   sudo apt-get update
   [ -e vagrant_1.8.5_x86_64.deb ] || wget https://releases.hashicorp.com/vagrant/1.8.5/vagrant_1.8.5_x86_64.deb
   sudo dpkg -i vagrant_1.8.5_x86_64.deb
-  sudo apt-get -y install qemu-kvm libvirt-bin libvirt-dev curl
+  sudo apt-get -y install qemu-kvm libvirt-bin libvirt-dev curl nfs-kernel-server
 
   [ -e ~/.ssh/id_rsa ] || ssh-keygen -t rsa -N "" -f ~/.ssh/id_rsa
   cat ~/.ssh/id_rsa.pub >> ~/.ssh/authorized_keys
@@ -99,7 +99,8 @@
 function cloudlab_setup() {
   if [ -e /usr/testbed/bin/mkextrafs ]
   then
-    sudo /usr/testbed/bin/mkextrafs -r /dev/sdb -qf "/var/lib/libvirt/images/"
+    # Sometimes this command fails on the first try
+    sudo /usr/testbed/bin/mkextrafs -r /dev/sdb -qf "/var/lib/libvirt/images/" || sudo /usr/testbed/bin/mkextrafs -r /dev/sdb -qf "/var/lib/libvirt/images/"
 
     cd $CORDDIR/build
     SRC="#- 'on_cloudlab=True'"