diff --git a/util/install.sh b/util/install.sh
index 0c187f4..1908904 100755
--- a/util/install.sh
+++ b/util/install.sh
@@ -557,6 +557,7 @@ function all {
 function vm_clean {
     echo "Cleaning VM..."
     sudo apt-get clean
+    sudo apt-get autoremove
     sudo rm -rf /tmp/*
     sudo rm -rf openvswitch*.tar.gz
 
@@ -577,6 +578,9 @@ function vm_clean {
     git config --global user.name "None"
     git config --global user.email "None"
 
+    echo "Zeroing out file blocks for efficient compaction"
+    time sudo cp /dev/zero /tmp/; sync ; sleep 1 ; sync ; sudo rm -f /tmp/zero
+
 }
 
 function usage {