diff --git a/roles/osd/defaults/main.yml b/roles/osd/defaults/main.yml
index 9c74769..9eaec8e 100644
--- a/roles/osd/defaults/main.yml
+++ b/roles/osd/defaults/main.yml
@@ -19,3 +19,5 @@ ceph_osd_osds_group: "{{ ceph_osd_group | default('cephs') }}"
 # Filesystem ID
 ceph_mon_fsid: "{{ ceph_fsid }}"
 cephadm_image: "quay.io/ceph/ceph:v{{ ceph_version | default('18.2.1') }}"
+
+ceph_bluestore_frag_collect: true
diff --git a/roles/osd/tasks/main.yml b/roles/osd/tasks/main.yml
index 8b4d4fc..852e0c7 100644
--- a/roles/osd/tasks/main.yml
+++ b/roles/osd/tasks/main.yml
@@ -126,3 +126,28 @@
   ansible.builtin.include_tasks: check-osds.yml
   when:
     - inventory_hostname == groups[ceph_osd_osds_group] | last
+
+- name: Prepare Cronjob script for collect Bluestore fragmentation score
+  when: ceph_bluestore_frag_collect
+  ansible.builtin.copy:
+    src: "bs-frag-score.sh.j2"
+    dest: "/var/lib/cron/bs-frag-score.sh"
+    owner: root
+    group: root
+    mode: u+rwx,g=,o=
+
+- name: Prepare Cronjob script for collect Bluestore fragmentation score
+  when: ceph_bluestore_frag_collect
+  ansible.builtin.templates:
+    src: "prom-bs-frag-score-collector.sh.j2"
+    dest: "/var/lib/cron/prom-bs-frag-score-collector.sh"
+    owner: root
+    group: root
+    mode: u+rwx,g=,o=
+
+- name: Setup Cron job collect Bluestore fragmentation score for Prometheus
+  when: ceph_bluestore_frag_collect
+  ansible.builtin.cron:
+    name: "collect bluestore fragmentation score"
+    minute: "1"
+    job: "/var/lib/cron/prom-bs-frag-score-collector.sh"
diff --git a/roles/osd/templates/bs-frag-score.sh.j2 b/roles/osd/templates/bs-frag-score.sh.j2
new file mode 100644
index 0000000..c433e3d
--- /dev/null
+++ b/roles/osd/templates/bs-frag-score.sh.j2
@@ -0,0 +1,4 @@
+#!/bin/bash
+# {{ ansible_managed }}
+
+ceph-volume lvm list|grep "osd id" |grep -o [0-9]*| xargs -i sh -c 'echo bluestore_allocator_score_block{osd=osd.{}} $(ceph daemon osd.{} bluestore allocator score block | grep fragmentation_rating|cut -d ':' -f2) $(date +%s)'
diff --git a/roles/osd/templates/prom-bs-frag-score-collector.sh.j2 b/roles/osd/templates/prom-bs-frag-score-collector.sh.j2
new file mode 100644
index 0000000..5fb33cb
--- /dev/null
+++ b/roles/osd/templates/prom-bs-frag-score-collector.sh.j2
@@ -0,0 +1,15 @@
+#!/bin/bash
+# {{ ansible_managed }}
+
+export TMPFILE=/tmp/bluestore_allocator_score_block.prom.$$
+osd_path=$(find /var/lib/ceph/{{ ceph_mon_fsid }}/ -type d -name "osd.*"|  head -n 1)
+if [ -z $osd_path ]; then
+    cephadm --image "{{ cephadm_image }}" shell --fsid "{{ ceph_mon_fsid }}" \
+      --config "$osd_path/config" \
+      -m /var/lib/cron/bs-frag-score.sh -- ./mnt/bs-frag-score.sh > TMPFILE
+else
+    cephadm --image "{{ cephadm_image }}" shell --fsid "{{ ceph_mon_fsid }}" \
+      -m /var/lib/cron/bs-frag-score.sh -- ./mnt/bs-frag-score.sh > TMPFILE
+fi
+
+mv $TMPFILE /tmp/bluestore_allocator_score_block.prom