diff --git a/cluster/aws/config-default.sh b/cluster/aws/config-default.sh
index 147864b9c63..74f90b1e9b0 100644
--- a/cluster/aws/config-default.sh
+++ b/cluster/aws/config-default.sh
@@ -39,6 +39,12 @@ LOG="/dev/null"
 
 MASTER_DISK_TYPE="${MASTER_DISK_TYPE:-gp2}"
 MASTER_DISK_SIZE=${MASTER_DISK_SIZE:-20}
+# The master root EBS volume size (typically does not need to be very large)
+MASTER_ROOT_DISK_TYPE="${MASTER_ROOT_DISK_TYPE:-gp2}"
+MASTER_ROOT_DISK_SIZE=${MASTER_ROOT_DISK_SIZE:-8}
+# The minions root EBS volume size (used to house Docker images
+MINION_ROOT_DISK_TYPE="${MINION_ROOT_DISK_TYPE:-gp2}"
+MINION_ROOT_DISK_SIZE=${MINION_ROOT_DISK_SIZE:-32}
 
 MASTER_NAME="${INSTANCE_PREFIX}-master"
 MASTER_TAG="${INSTANCE_PREFIX}-master"
@@ -93,4 +99,3 @@ KUBE_MINION_IMAGE="${KUBE_MINION_IMAGE:-}"
 COREOS_CHANNEL="${COREOS_CHANNEL:-alpha}"
 CONTAINER_RUNTIME="${KUBE_CONTAINER_RUNTIME:-docker}"
 RKT_VERSION="${KUBE_RKT_VERSION:-0.5.5}"
-
diff --git a/cluster/aws/util.sh b/cluster/aws/util.sh
index ae6c5c22678..c7e4cb717a6 100644
--- a/cluster/aws/util.sh
+++ b/cluster/aws/util.sh
@@ -63,7 +63,9 @@ MINION_SG_NAME="kubernetes-minion-${CLUSTER_ID}"
 # Be sure to map all the ephemeral drives.  We can specify more than we actually have.
 # TODO: Actually mount the correct number (especially if we have more), though this is non-trivial, and
 #  only affects the big storage instance types, which aren't a typical use case right now.
-BLOCK_DEVICE_MAPPINGS="[{\"DeviceName\": \"/dev/sdc\",\"VirtualName\":\"ephemeral0\"},{\"DeviceName\": \"/dev/sdd\",\"VirtualName\":\"ephemeral1\"},{\"DeviceName\": \"/dev/sde\",\"VirtualName\":\"ephemeral2\"},{\"DeviceName\": \"/dev/sdf\",\"VirtualName\":\"ephemeral3\"}]"
+BLOCK_DEVICE_MAPPINGS_BASE="{\"DeviceName\": \"/dev/sdc\",\"VirtualName\":\"ephemeral0\"},{\"DeviceName\": \"/dev/sdd\",\"VirtualName\":\"ephemeral1\"},{\"DeviceName\": \"/dev/sde\",\"VirtualName\":\"ephemeral2\"},{\"DeviceName\": \"/dev/sdf\",\"VirtualName\":\"ephemeral3\"}"
+MASTER_BLOCK_DEVICE_MAPPINGS="[{\"DeviceName\":\"/dev/sda1\",\"Ebs\":{\"DeleteOnTermination\":true,\"VolumeSize\":${MASTER_ROOT_DISK_SIZE},\"VolumeType\":\"${MASTER_ROOT_DISK_TYPE}\"}}, ${BLOCK_DEVICE_MAPPINGS_BASE}]"
+MINION_BLOCK_DEVICE_MAPPINGS="[{\"DeviceName\":\"/dev/sda1\",\"Ebs\":{\"DeleteOnTermination\":true,\"VolumeSize\":${MINION_ROOT_DISK_SIZE},\"VolumeType\":\"${MINION_ROOT_DISK_TYPE}\"}}, ${BLOCK_DEVICE_MAPPINGS_BASE}]"
 
 function json_val {
     python -c 'import json,sys;obj=json.load(sys.stdin);print obj'$1''
@@ -846,7 +848,7 @@ function kube-up {
     --key-name ${AWS_SSH_KEY_NAME} \
     --security-group-ids ${MASTER_SG_ID} \
     --associate-public-ip-address \
-    --block-device-mappings "${BLOCK_DEVICE_MAPPINGS}" \
+    --block-device-mappings "${MASTER_BLOCK_DEVICE_MAPPINGS}" \
     --user-data file://${KUBE_TEMP}/master-start.sh | json_val '["Instances"][0]["InstanceId"]')
   add-tag $master_id Name $MASTER_NAME
   add-tag $master_id Role $MASTER_TAG
@@ -957,7 +959,7 @@ function kube-up {
       --key-name ${AWS_SSH_KEY_NAME} \
       --security-groups ${MINION_SG_ID} \
       ${public_ip_option} \
-      --block-device-mappings "${BLOCK_DEVICE_MAPPINGS}" \
+      --block-device-mappings "${MINION_BLOCK_DEVICE_MAPPINGS}" \
       --user-data "file://${KUBE_TEMP}/minion-user-data"
 
   echo "Creating autoscaling group"