diff --git a/micro-osd.sh b/micro-osd.sh
index c6009d0..d5fe209 100755
--- a/micro-osd.sh
+++ b/micro-osd.sh
@@ -38,10 +38,14 @@ RGW_ID="r"
 S3_ACCESS_KEY=2262XNX11FZRR44XWIRD
 S3_SECRET_KEY=rmtuS1Uj1bIC08QFYGW18GfSHAbkPqdsuYynNudw
 
-# cluster wide parameters
-cat >> ${DIR}/ceph.conf <<EOF
+FSID="$(uuidgen)"
+export CEPH_CONF=${DIR}/ceph.conf
+
+generate_ceph_conf() {
+    # cluster wide parameters
+    cat >> "${CEPH_CONF}" <<EOF
 [global]
-fsid = $(uuidgen)
+fsid = ${FSID}
 osd crush chooseleaf type = 0
 run dir = ${DIR}/run
 auth cluster required = none
@@ -85,76 +89,102 @@ rgw usage max user shards = 1
 log file = /var/log/ceph/client.rgw.${RGW_ID}.log
 rgw frontends = beast port=80
 EOF
+}
 
-export CEPH_CONF=${DIR}/ceph.conf
+launch_mon() {
+    ceph-mon --id ${MON_NAME} --mkfs --keyring /dev/null
+    touch ${MON_DATA}/keyring
+    ceph-mon --id ${MON_NAME}
+}
 
-# start an osd
-ceph-mon --id ${MON_NAME} --mkfs --keyring /dev/null
-touch ${MON_DATA}/keyring
-ceph-mon --id ${MON_NAME}
+launch_osd() {
+    OSD_ID=$(ceph osd create)
+    ceph osd crush add osd.${OSD_ID} 1 root=default
+    ceph-osd --id ${OSD_ID} --mkjournal --mkfs
+    ceph-osd --id ${OSD_ID} || ceph-osd --id ${OSD_ID} || ceph-osd --id ${OSD_ID}
+}
 
-# start an osd
-OSD_ID=$(ceph osd create)
-ceph osd crush add osd.${OSD_ID} 1 root=default
-ceph-osd --id ${OSD_ID} --mkjournal --mkfs
-ceph-osd --id ${OSD_ID} || ceph-osd --id ${OSD_ID} || ceph-osd --id ${OSD_ID}
+launch_mds() {
+    ceph auth get-or-create mds.${MDS_NAME} mon 'profile mds' mgr 'profile mds' mds 'allow *' osd 'allow *' > ${MDS_DATA}/keyring
+    ceph osd pool create cephfs_data 8
+    ceph osd pool create cephfs_metadata 8
+    ceph fs new cephfs cephfs_metadata cephfs_data
+    ceph fs ls
+    ceph-mds -i ${MDS_NAME}
+    ceph status
+    while [[ ! $(ceph mds stat | grep "up:active") ]]; do sleep 1; done
+}
 
-# start an mds for cephfs
-ceph auth get-or-create mds.${MDS_NAME} mon 'profile mds' mgr 'profile mds' mds 'allow *' osd 'allow *' > ${MDS_DATA}/keyring
-ceph osd pool create cephfs_data 8
-ceph osd pool create cephfs_metadata 8
-ceph fs new cephfs cephfs_metadata cephfs_data
-ceph fs ls
-ceph-mds -i ${MDS_NAME}
-ceph status
-while [[ ! $(ceph mds stat | grep "up:active") ]]; do sleep 1; done
+launch_mgr() {
+    ceph-mgr --id ${MGR_NAME}
+}
 
+launch_rbd_mirror() {
+    ceph auth get-or-create client.rbd-mirror.${MIRROR_ID} mon 'profile rbd-mirror' osd 'profile rbd'
+    rbd-mirror --id ${MIRROR_ID} --log-file ${LOG_DIR}/rbd-mirror.log
+}
 
-# start a manager
-ceph-mgr --id ${MGR_NAME}
+launch_cephfs_mirror() {
+    ceph auth get-or-create "client.cephfs-mirror.${MIRROR_ID}" \
+        mon 'profile cephfs-mirror' \
+        mds 'allow r' \
+        osd 'allow rw tag cephfs metadata=*, allow r tag cephfs data=*' \
+        mgr 'allow r'
+    cephfs-mirror --id "cephfs-mirror.${MIRROR_ID}" \
+        --log-file "${LOG_DIR}/cephfs-mirror.log"
+    ceph fs authorize cephfs client.cephfs-mirror-remote / rwps > "${DIR}/cephfs-mirror-remote.out"
+    # the .out file above is not used by the scripts but can be used for debugging
+}
 
-# start rbd-mirror
-ceph auth get-or-create client.rbd-mirror.${MIRROR_ID} mon 'profile rbd-mirror' osd 'profile rbd'
-rbd-mirror --id ${MIRROR_ID} --log-file ${LOG_DIR}/rbd-mirror.log
+launch_radosgw() {
+    ceph auth get-or-create client.rgw."${RGW_ID}" osd 'allow rwx' mon 'allow rw' -o ${RGW_DATA}/keyring
+    radosgw -n client.rgw."${RGW_ID}" -k ${RGW_DATA}/keyring
+    timeout 60 sh -c 'until [ $(ceph -s | grep -c "rgw:") -eq 1 ]; do echo "waiting for rgw to show up" && sleep 1; done'
+    radosgw-admin user create --uid admin --display-name "Admin User" --caps "buckets=*;users=*;usage=read;metadata=read" --access-key="$S3_ACCESS_KEY" --secret-key="$S3_SECRET_KEY"
+}
 
-# start cephfs-mirror
-# Skip on "nautilus" and "octopus" the supported ceph versions that
-# don't have it.
-case "${CEPH_VERSION}" in
-    nautilus|octopus)
-        echo "Skipping cephfs-mirror on ${CEPH_VERSION} ..."
-    ;;
-    *)
-        ceph auth get-or-create "client.cephfs-mirror.${MIRROR_ID}" \
-            mon 'profile cephfs-mirror' \
-            mds 'allow r' \
-            osd 'allow rw tag cephfs metadata=*, allow r tag cephfs data=*' \
-            mgr 'allow r'
-        cephfs-mirror --id "cephfs-mirror.${MIRROR_ID}" \
-            --log-file "${LOG_DIR}/cephfs-mirror.log"
-        ceph fs authorize cephfs client.cephfs-mirror-remote / rwps > "${DIR}/cephfs-mirror-remote.out"
-        # the .out file above is not used by the scripts but can be used for debugging
-    ;;
-esac
+selftest() {
+    ceph --version
+    ceph status
+    test_pool=$(uuidgen)
+    temp_file=$(mktemp)
+    ceph osd pool create ${test_pool} 0
+    rados --pool ${test_pool} put group /etc/group
+    rados --pool ${test_pool} get group ${temp_file}
+    diff /etc/group ${temp_file}
+    ceph osd pool delete ${test_pool} ${test_pool} --yes-i-really-really-mean-it
+    rm ${temp_file}
+}
 
+FEATURESET="${CEPH_FEATURESET}"
+if [ -z "$FEATURESET" ] ; then
+    case "${CEPH_VERSION}" in
+        nautilus|octopus)
+            FEATURESET="mon osd mgr mds rbd-mirror rgw selftest"
+        ;;
+        *)
+            FEATURESET="mon osd mgr mds rbd-mirror cephfs-mirror rgw selftest"
+        ;;
+    esac
+fi
 
-# start an rgw
-ceph auth get-or-create client.rgw."${RGW_ID}" osd 'allow rwx' mon 'allow rw' -o ${RGW_DATA}/keyring
-radosgw -n client.rgw."${RGW_ID}" -k ${RGW_DATA}/keyring
-timeout 60 sh -c 'until [ $(ceph -s | grep -c "rgw:") -eq 1 ]; do echo "waiting for rgw to show up" && sleep 1; done'
-radosgw-admin user create --uid admin --display-name "Admin User" --caps "buckets=*;users=*;usage=read;metadata=read" --access-key="$S3_ACCESS_KEY" --secret-key="$S3_SECRET_KEY"
-
-# test the setup
-ceph --version
-ceph status
-test_pool=$(uuidgen)
-temp_file=$(mktemp)
-ceph osd pool create ${test_pool} 0
-rados --pool ${test_pool} put group /etc/group
-rados --pool ${test_pool} get group ${temp_file}
-diff /etc/group ${temp_file}
-ceph osd pool delete ${test_pool} ${test_pool} --yes-i-really-really-mean-it
-rm ${temp_file}
+generate_ceph_conf
+for fname in ${FEATURESET}; do
+    case "${fname}" in
+        mon) launch_mon ;;
+        osd) launch_osd ;;
+        mds) launch_mds ;;
+        mgr) launch_mgr ;;
+        rbd-mirror) launch_rbd_mirror ;;
+        cephfs-mirror) launch_cephfs_mirror ;;
+        rgw|radosgw) launch_radosgw ;;
+        selftest) selftest ;;
+        *)
+            echo "Invalid feature: ${fname}"
+            exit 2
+        ;;
+    esac
+done
 
 touch ${DIR}/.ready