diff --git a/charts/kube-prometheus-stack/charts/prometheus-node-exporter/templates/daemonset.yaml b/charts/kube-prometheus-stack/charts/prometheus-node-exporter/templates/daemonset.yaml
index 23896a230..af3525ff9 100644
--- a/charts/kube-prometheus-stack/charts/prometheus-node-exporter/templates/daemonset.yaml
+++ b/charts/kube-prometheus-stack/charts/prometheus-node-exporter/templates/daemonset.yaml
@@ -165,7 +165,7 @@ spec:
             {{- range $_, $mount := .Values.sidecarVolumeMount }}
             - name: {{ $mount.name }}
               mountPath: {{ $mount.mountPath }}
-              readOnly: true
+              readOnly: {{ $mount.readOnly }}
             {{- end }}
             {{- range $_, $mount := .Values.configmaps }}
             - name: {{ $mount.name }}
diff --git a/charts/patches/kube-prometheus-stack/0000-fix-node-exporter-sidecar-volume.patch b/charts/patches/kube-prometheus-stack/0000-fix-node-exporter-sidecar-volume.patch
new file mode 100644
index 000000000..f9419ec75
--- /dev/null
+++ b/charts/patches/kube-prometheus-stack/0000-fix-node-exporter-sidecar-volume.patch
@@ -0,0 +1,13 @@
+diff --git a/kube-prometheus-stack/charts/prometheus-node-exporter/templates/daemonset.yaml b/charts/kube-prometheus-stack/charts/prometheus-node-exporter/templates/daemonset.yaml
+index 23896a23..af3525ff 100644
+--- a/kube-prometheus-stack/charts/prometheus-node-exporter/templates/daemonset.yaml
++++ b/charts/kube-prometheus-stack/charts/prometheus-node-exporter/templates/daemonset.yaml
+@@ -165,7 +165,7 @@ spec:
+             {{- range $_, $mount := .Values.sidecarVolumeMount }}
+             - name: {{ $mount.name }}
+               mountPath: {{ $mount.mountPath }}
+-              readOnly: true
++              readOnly: {{ $mount.readOnly }}
+             {{- end }}
+             {{- range $_, $mount := .Values.configmaps }}
+             - name: {{ $mount.name }}
diff --git a/roles/kube_prometheus_stack/files/jsonnet/mixins.libsonnet b/roles/kube_prometheus_stack/files/jsonnet/mixins.libsonnet
index 7c8c45eb4..f80bce0a1 100644
--- a/roles/kube_prometheus_stack/files/jsonnet/mixins.libsonnet
+++ b/roles/kube_prometheus_stack/files/jsonnet/mixins.libsonnet
@@ -87,6 +87,39 @@ local mixins = {
             },
           ],
         },
+        {
+          name: 'bluestore-fragmentation-score',
+          rules: [
+            {
+              alert: 'BluestoreFragmentationScoreConsiderable',
+              annotations: {
+                description: 'Bluestore fragmentation score for osd {{ $labels.osd }} on host {{ $labels.instance }} is currently at {{ $value }}. If it continue to goes higher then 0.9, it will impact other running services.',
+                summary: '[{{ $labels.osd }}] reaching a considerable value: {{ $value }}',
+              },
+              'for': '1m',
+              expr: |||
+                bluestore_allocator_score_block > 0.7
+              |||,
+              labels: {
+                severity: 'warning',
+              },
+            },
+            {
+              alert: 'BluestoreFragmentationScoreHigh',
+              annotations: {
+                description: 'Bluestore fragmentation score for osd {{ $labels.osd }} on host {{ $labels.instance }} is currently at {{ $value }}. It might impact other running services.',
+                summary: '[{{ $labels.osd }}] reaching a high value: {{ $value }}',
+              },
+              'for': '1m',
+              expr: |||
+                bluestore_allocator_score_block > 0.9
+              |||,
+              labels: {
+                severity: 'P3',
+              },
+            }
+          ],
+        },
       ],
     }
   },
diff --git a/roles/kube_prometheus_stack/vars/main.yml b/roles/kube_prometheus_stack/vars/main.yml
index 1a0be777b..761e7f7c6 100644
--- a/roles/kube_prometheus_stack/vars/main.yml
+++ b/roles/kube_prometheus_stack/vars/main.yml
@@ -554,7 +554,73 @@ _kube_prometheus_stack_helm_values:
       - --collector.processes
       - --collector.systemd
       - --collector.stat.softirq
+      - --collector.textfile.directory=/tmp
     prometheus:
       monitor:
         relabelings: *relabelings_instance_to_node_name
+    securityContext:
+      runAsNonRoot: false
+    sidecars:
+      - name: ceph-osd-bs-collector
+        image: "{{ atmosphere_images['ceph'] }}"
+        resources:
+          limits:
+            cpu: 100m
+            memory: 300Mi
+          requests:
+            cpu: 100m
+            memory: 300Mi
+        securityContext:
+          privileged: true
+          runAsUser: 0
+        command:
+          - /bin/bash
+          - /var/lib/cron/prom-bs-frag-score-collector.sh
+        volumeMounts:
+          - name: kube-prometheus-stack-node-ceph-bs
+            mountPath: /var/lib/cron/prom-bs-frag-score-collector.sh
+            subPath: prom-bs-frag-score-collector.sh
+    sidecarVolumeMount:
+      - name: pod-tmp
+        mountPath: /tmp
+        emptyDir: {}
+        readOnly: false
+    configmaps:
+      - name: kube-prometheus-stack-node-ceph-bs
+        mountPath: /var/lib/cron
+        configMap:
+          name: kube-prometheus-stack-node-ceph-bs
+          defaultMode: "0755"
+    sidecarHostVolumeMounts:
+      - name: ceph-var
+        hostPath: /var/lib/ceph
+        mountPath: /var/lib/ceph
+        readOnly: true
+      - name: varrun
+        hostPath: /var/run
+        mountPath: /var/run
+        readOnly: true
+    extraManifests:
+      - |
+        apiVersion: v1
+        kind: ConfigMap
+        metadata:
+          name: kube-prometheus-stack-node-ceph-bs
+        data:
+          prom-bs-frag-score-collector.sh: |
+            #!/bin/bash
+            set -ex
+            export ceph_mon_fsid="{{ ceph_mon_fsid }}"
+            export PATH="/usr/local/bin:/usr/bin:/bin:/usr/sbin"
+            function bs_frag_score () {
+                ceph-volume --log-path /tmp lvm list | grep "osd id" | grep -o [0-9]*| xargs -i sh -c 'echo bluestore_allocator_score_block{osd=\"osd.{}\"} $(ceph daemon /var/run/ceph/$ceph_mon_fsid/ceph-osd.{}.asok bluestore allocator score block | grep fragmentation_rating|cut -d ':' -f2)'
+            }
+            function collect_bs_frag_score () {
+                echo "Start collecting Bluestore fragmentation score"
+                export TMPFILE=/tmp/bluestore_allocator_score_block.prom.$$
+                echo "# TYPE bluestore_allocator_score_block gauge" > $TMPFILE
+                bs_frag_score >> $TMPFILE
+                mv $TMPFILE /tmp/bluestore_allocator_score_block.prom
+            }
+            while true; do collect_bs_frag_score ; sleep 60 ; done
   additionalPrometheusRulesMap: "{{ lookup('vexxhost.atmosphere.jsonnet', 'jsonnet/rules.jsonnet') }}"