diff --git a/harddrive-install-tree.sh b/harddrive-install-tree.sh
index 2ed96cf2..8a5f3300 100755
--- a/harddrive-install-tree.sh
+++ b/harddrive-install-tree.sh
@@ -29,7 +29,7 @@ prepare_disks() {
     tmpdir=$1
 
     qemu-img create -q -f qcow2 ${tmpdir}/disk-a.img 10G
-    qemu-img create -q -f qcow2 ${tmpdir}/disk-b.img 12G
+    qemu-img create -q -f qcow2 ${tmpdir}/disk-b.img 22G
 
     echo ${tmpdir}/disk-a.img ${tmpdir}/disk-b.img
 }