diff --git a/site-cookbooks/kosmos_kvm/files/create_vm b/site-cookbooks/kosmos_kvm/files/create_vm
index db4cf8e..0c82f2d 100644
--- a/site-cookbooks/kosmos_kvm/files/create_vm
+++ b/site-cookbooks/kosmos_kvm/files/create_vm
@@ -5,13 +5,14 @@ if [[ $# -lt 3 ]] ; then
     cat <<-EOF
 USAGE (RAM in megabytes)
 
-create_vm VMNAME RAM CPUS
+create_vm VMNAME RAM CPUS DISKSIZE
 EOF
     exit 1
 fi
 VMNAME=$1
 RAM=$2
 CPUS=$3
+DISKSIZE=${4:-10} # 10GB default
 
 # Directory where image files will be stored
 IMAGE_DIR=/var/lib/libvirt/images
@@ -20,9 +21,6 @@ IMAGE_PATH=$IMAGE_DIR/$IMAGE_FILE
 CIDATA_PATH=${IMAGE_DIR}/cidata-${VMNAME}.iso
 BASE_FILE=${IMAGE_DIR}/base/ubuntu-20.04-server-cloudimg-amd64-disk-kvm.qcow2
 
-# Disk size assigned to the VM
-DISKSIZE=10  # Unit: GB
-
 # Create the VM image if it does not already exist
 if [ ! -f "$IMAGE_PATH" ]; then
   echo "info: image file $IMAGE_PATH not found. creating new image"