diff --git a/group_vars/iscsigws.yml.sample b/group_vars/iscsigws.yml.sample
index 5dfe68d20..4ab76d2c5 100644
--- a/group_vars/iscsigws.yml.sample
+++ b/group_vars/iscsigws.yml.sample
@@ -64,7 +64,7 @@ dummy:
 # Whether or not to generate secure certificate to iSCSI gateway nodes
 #generate_crt: False
 
-#rbd_pool_size: ""
+#rbd_pool_size: "{{ osd_pool_default_size }}"
 
 ##################
 # RBD-TARGET-API #
diff --git a/roles/ceph-client/tasks/create_users_keys.yml b/roles/ceph-client/tasks/create_users_keys.yml
index cd2eb0cef..9151c695d 100644
--- a/roles/ceph-client/tasks/create_users_keys.yml
+++ b/roles/ceph-client/tasks/create_users_keys.yml
@@ -122,13 +122,13 @@
     - name: customize pool size
       command: >
         {{ docker_exec_cmd | default('') }} ceph --cluster {{ cluster }}
-        osd pool set {{ item.name }} size {{ item.size | default('') }}
+        osd pool set {{ item.name }} size {{ item.size | default(osd_pool_default_size) }}
       with_items: "{{ pools | unique }}"
       delegate_to: "{{ delegated_node }}"
       changed_when: false
       when:
         - pools | length > 0
-        - item.size | default ("") != ""
+        - item.size | default(osd_pool_default_size) != ceph_osd_pool_default_size
 
 - name: get client cephx keys
   copy:
diff --git a/roles/ceph-defaults/tasks/facts.yml b/roles/ceph-defaults/tasks/facts.yml
index 39b28555c..4a3f6cf4c 100644
--- a/roles/ceph-defaults/tasks/facts.yml
+++ b/roles/ceph-defaults/tasks/facts.yml
@@ -244,5 +244,9 @@
   set_fact:
     osd_pool_default_pg_num: "{{ ceph_conf_overrides.get('global', {}).get('osd_pool_default_pg_num', ceph_osd_pool_default_pg_num) }}"
 
+- name: set_fact osd_pool_default_size
+  set_fact:
+    osd_pool_default_size: "{{ ceph_conf_overrides.get('global', {}).get('osd_pool_default_size', ceph_osd_pool_default_size) }}"
+
 - name: populate service facts
   service_facts:
diff --git a/roles/ceph-iscsi-gw/defaults/main.yml b/roles/ceph-iscsi-gw/defaults/main.yml
index 5ec740b14..5ffd64bb7 100644
--- a/roles/ceph-iscsi-gw/defaults/main.yml
+++ b/roles/ceph-iscsi-gw/defaults/main.yml
@@ -56,7 +56,7 @@ client_connections: {}
 # Whether or not to generate secure certificate to iSCSI gateway nodes
 generate_crt: False
 
-rbd_pool_size: ""
+rbd_pool_size: "{{ osd_pool_default_size }}"
 
 ##################
 # RBD-TARGET-API #
diff --git a/roles/ceph-iscsi-gw/tasks/common.yml b/roles/ceph-iscsi-gw/tasks/common.yml
index a40b75506..3d4a556fd 100644
--- a/roles/ceph-iscsi-gw/tasks/common.yml
+++ b/roles/ceph-iscsi-gw/tasks/common.yml
@@ -41,8 +41,8 @@
       delegate_to: "{{ groups[mon_group_name][0] }}"
 
     - name: customize pool size
-      command: "{{ docker_exec_cmd | default('') }} ceph --cluster {{ cluster }} osd pool set rbd size {{ rbd_pool_size | default('') }}"
+      command: "{{ docker_exec_cmd | default('') }} ceph --cluster {{ cluster }} osd pool set rbd size {{ rbd_pool_size | default(osd_pool_default_size) }}"
       delegate_to: "{{ groups[mon_group_name][0] }}"
       changed_when: false
       when:
-        - rbd_pool_size | default ("") != ""
+        - rbd_pool_size | default(osd_pool_default_size) != ceph_osd_pool_default_size
diff --git a/roles/ceph-mds/tasks/create_mds_filesystems.yml b/roles/ceph-mds/tasks/create_mds_filesystems.yml
index 0f9a5d451..208aa8ae0 100644
--- a/roles/ceph-mds/tasks/create_mds_filesystems.yml
+++ b/roles/ceph-mds/tasks/create_mds_filesystems.yml
@@ -9,11 +9,12 @@
         - "{{ cephfs_pools }}"
 
     - name: customize pool size
-      command: "{{ hostvars[groups[mon_group_name][0]]['docker_exec_cmd'] | default('') }} ceph --cluster {{ cluster }} osd pool set {{ item.name }} size {{ item.size | default('') }}"
+      command: "{{ hostvars[groups[mon_group_name][0]]['docker_exec_cmd'] | default('') }} ceph --cluster {{ cluster }} osd pool set {{ item.name }} size {{ item.size | default(osd_pool_default_size) }}"
       with_items: "{{ cephfs_pools | unique }}"
       delegate_to: "{{ groups[mon_group_name][0] }}"
       changed_when: false
-      when: item.size | default ("") != ""
+      when:
+        - item.size | default(osd_pool_default_size) != ceph_osd_pool_default_size
 
 - name: check if ceph filesystem already exists
   command: "{{ hostvars[groups[mon_group_name][0]]['docker_exec_cmd'] | default('') }} ceph --cluster {{ cluster }} fs get {{ cephfs }}"
diff --git a/roles/ceph-osd/tasks/openstack_config.yml b/roles/ceph-osd/tasks/openstack_config.yml
index c42d1f985..4bc3bbf9f 100644
--- a/roles/ceph-osd/tasks/openstack_config.yml
+++ b/roles/ceph-osd/tasks/openstack_config.yml
@@ -43,11 +43,12 @@
     - name: customize pool size
       command: >
         {{ hostvars[groups[mon_group_name][0]]['docker_exec_cmd'] | default('') }} ceph --cluster {{ cluster }}
-        osd pool set {{ item.name }} size {{ item.size | default('') }}
+        osd pool set {{ item.name }} size {{ item.size | default(osd_pool_default_size) }}
       with_items: "{{ openstack_pools | unique }}"
       delegate_to: "{{ groups[mon_group_name][0] }}"
       changed_when: false
-      when: item.size | default ("") != ""
+      when:
+        - item.size | default(osd_pool_default_size) != ceph_osd_pool_default_size
 
     - name: assign application to pool(s)
       command: "{{ hostvars[groups[mon_group_name][0]]['docker_exec_cmd'] | default('') }} ceph --cluster {{ cluster }} osd pool application enable {{ item.name }} {{ item.application }}"
diff --git a/roles/ceph-rgw/tasks/main.yml b/roles/ceph-rgw/tasks/main.yml
index e239c113c..f3941b126 100644
--- a/roles/ceph-rgw/tasks/main.yml
+++ b/roles/ceph-rgw/tasks/main.yml
@@ -34,9 +34,10 @@
       run_once: true
 
     - name: customize pool size
-      command: "{{ docker_exec_cmd }} ceph --connect-timeout 5 --cluster {{ cluster }} osd pool set {{ item.key }} size {{ item.size | default('') }}"
+      command: "{{ docker_exec_cmd }} ceph --connect-timeout 5 --cluster {{ cluster }} osd pool set {{ item.key }} size {{ item.size | default(osd_pool_default_size) }}"
       with_dict: "{{ rgw_create_pools }}"
       delegate_to: "{{ groups[mon_group_name][0] }}"
       changed_when: false
       run_once: true
-      when: item.size | default ("") != ""
+      when:
+        - item.size | default(osd_pool_default_size) != ceph_osd_pool_default_size