diff --git a/ansible/roles/common/templates/conf/output/00-local.conf.j2 b/ansible/roles/common/templates/conf/output/00-local.conf.j2
index 6d053513ee..8bb1f9c082 100644
--- a/ansible/roles/common/templates/conf/output/00-local.conf.j2
+++ b/ansible/roles/common/templates/conf/output/00-local.conf.j2
@@ -52,6 +52,9 @@
        buffer_path /var/lib/fluentd/data/monasca.buffer/{{ syslog_swift_facility }}.*
        max_retry_wait 1800s
        disable_retry_limit true
+       <buffer>
+         chunk_limit_size 8m
+       </buffer>
     </store>
 {% endif %}
 </match>
@@ -112,6 +115,9 @@
        buffer_path /var/lib/fluentd/data/monasca.buffer/{{ syslog_haproxy_facility }}.*
        max_retry_wait 1800s
        disable_retry_limit true
+       <buffer>
+         chunk_limit_size 8m
+       </buffer>
     </store>
 {% endif %}
 </match>
@@ -169,6 +175,9 @@
        buffer_path /var/lib/fluentd/data/monasca.buffer/{{ syslog_glance_tls_proxy_facility }}.*
        max_retry_wait 1800s
        disable_retry_limit true
+       <buffer>
+         chunk_limit_size 8m
+       </buffer>
     </store>
 {% endif %}
 </match>
diff --git a/ansible/roles/common/templates/conf/output/02-monasca.conf.j2 b/ansible/roles/common/templates/conf/output/02-monasca.conf.j2
index f0d9cc5923..7a680784de 100644
--- a/ansible/roles/common/templates/conf/output/02-monasca.conf.j2
+++ b/ansible/roles/common/templates/conf/output/02-monasca.conf.j2
@@ -14,5 +14,8 @@
        buffer_path /var/lib/fluentd/data/monasca.buffer/openstack.*
        max_retry_wait 1800s
        disable_retry_limit true
+       <buffer>
+         chunk_limit_size 8m
+       </buffer>
     </store>
 </match>
diff --git a/releasenotes/notes/fix-fluentd-buffer-chunk-size-for-monasca-output-882338103d2e1f13.yaml b/releasenotes/notes/fix-fluentd-buffer-chunk-size-for-monasca-output-882338103d2e1f13.yaml
new file mode 100644
index 0000000000..d56706aede
--- /dev/null
+++ b/releasenotes/notes/fix-fluentd-buffer-chunk-size-for-monasca-output-882338103d2e1f13.yaml
@@ -0,0 +1,8 @@
+---
+fixes:
+  - |
+    Fixes `LP#1885885
+    <https://bugs.launchpad.net/kolla-ansible/+bug/1885885>`__ where the
+    default chunk size in the Monasca Fluentd output plugin increased from
+    8MB to 256MB for file buffering which exceeded the limit allowed by
+    the Monasca Log / Unified API.