diff --git a/roles/nfs-server/files/mknfshomedir.sh b/roles/nfs-server/files/mknfshomedir.sh
index 4bf7ff3..b243028 100755
--- a/roles/nfs-server/files/mknfshomedir.sh
+++ b/roles/nfs-server/files/mknfshomedir.sh
@@ -2,6 +2,9 @@
 
 set -e
 
+LOCKFILE="/run/$(basename "$0").pid"
+STATEFILE="/run/$(basename "$0").state"
+
 _basedn="$(awk '{ if ($1 == "BASE") print $2 }' /etc/openldap/ldap.conf)"
 if [ -z "$_basedn" ]; then
     logger -i -t "$(basename "$0")" -p user.error -s \
@@ -18,6 +21,40 @@ else
     exit 1
 fi
 
+if [ -f "$LOCKFILE" ]; then
+    if kill -0 "$(cat "${LOCKFILE}")" ; then
+        _started=" ($(stat --format='%y' ${LOCKFILE}))"
+        logger -i -t "$(basename "$0")" -p user.notice -s \
+            "ERROR: Lockfile exists${_started}"
+        exit 1
+    else
+        logger -i -t "$(basename "$0")" -p user.notice -s \
+            "WARN: Removing stale lock file"
+    fi
+fi
+trap 'rm -f ${LOCKFILE}' INT TERM EXIT
+echo "$$" > "$LOCKFILE"
+
+_state="$(
+    ldapsearch -Q -LLL -s base contextCSN | awk '
+        BEGIN { csn=0 }
+        {
+            if ($1 == "contextCSN:") {
+                val=substr($2, 0, 21);
+                if (val > csn) {
+                    csn = val
+                }
+            }
+        }
+        END { print csn }
+    '
+)"
+if [ -f "$STATEFILE" ]; then
+    if [ "$_state" == "$(cat "$STATEFILE")" ]; then
+        exit 0
+    fi
+fi
+
 ldapsearch -Q -LLL -b "ou=People,${_basedn}" "$_filter" automountInformation | \
     awk -v_hostname="$(hostname -f)" '{
         if ($1 == "automountInformation:") {
@@ -54,3 +91,5 @@ ldapsearch -Q -LLL -b "ou=People,${_basedn}" "$_filter" automountInformation | \
         install -d -o "$_user" -g "$_user" -m 0700 "$_target"
         su "$_user" -s /bin/bash -c "umask 077 ; cp -r /etc/skel/. '${_target}'"
     done
+
+echo "$_state" > "$STATEFILE"
diff --git a/roles/nfs-server/files/mknfsroledir.sh b/roles/nfs-server/files/mknfsroledir.sh
index 9c7df21..fd9e93d 100755
--- a/roles/nfs-server/files/mknfsroledir.sh
+++ b/roles/nfs-server/files/mknfsroledir.sh
@@ -2,6 +2,9 @@
 
 set -e
 
+LOCKFILE="/run/$(basename "$0").pid"
+STATEFILE="/run/$(basename "$0").state"
+
 _basedn="$(awk '{ if ($1 == "BASE") print $2 }' /etc/openldap/ldap.conf)"
 if [ -z "$_basedn" ]; then
     logger -i -t "$(basename "$0")" -p user.error -s \
@@ -18,6 +21,40 @@ else
     exit 1
 fi
 
+if [ -f "$LOCKFILE" ]; then
+    if kill -0 "$(cat "${LOCKFILE}")" ; then
+        _started=" ($(stat --format='%y' ${LOCKFILE}))"
+        logger -i -t "$(basename "$0")" -p user.notice -s \
+            "ERROR: Lockfile exists${_started}"
+        exit 1
+    else
+        logger -i -t "$(basename "$0")" -p user.notice -s \
+            "WARN: Removing stale lock file"
+    fi
+fi
+trap 'rm -f ${LOCKFILE}' INT TERM EXIT
+echo "$$" > "$LOCKFILE"
+
+_state="$(
+    ldapsearch -Q -LLL -s base contextCSN | awk '
+        BEGIN { csn=0 }
+        {
+            if ($1 == "contextCSN:") {
+                val=substr($2, 0, 21);
+                if (val > csn) {
+                    csn = val
+                }
+            }
+        }
+        END { print csn }
+    '
+)"
+if [ -f "$STATEFILE" ]; then
+    if [ "$_state" == "$(cat "$STATEFILE")" ]; then
+        exit 0
+    fi
+fi
+
 ldapsearch -Q -LLL -b "ou=Groups,${_basedn}" "$_filter" automountInformation | \
     awk -v_hostname="$(hostname -f)" '{
         if ($1 == "automountInformation:") {
@@ -52,3 +89,5 @@ ldapsearch -Q -LLL -b "ou=Groups,${_basedn}" "$_filter" automountInformation | \
         install -d -o root -g "$_role" -m 2770 "${_target}/library"
         install -d -o root -g "$_role" -m 2775 "${_target}/public"
     done
+
+echo "$_state" > "$STATEFILE"
diff --git a/roles/nfs-server/tasks/main.yml b/roles/nfs-server/tasks/main.yml
index d2cf66d..473b01c 100644
--- a/roles/nfs-server/tasks/main.yml
+++ b/roles/nfs-server/tasks/main.yml
@@ -32,7 +32,6 @@
   cron:
     name: "{{ item }}"
     user: root
-    minute: "*/15"
     job: "/usr/local/sbin/{{ item }}"
   with_items:
     - mknfshomedir