diff --git a/changelogs/asm_ausize.yml b/changelogs/asm_ausize.yml
new file mode 100644
index 000000000..ccee70cdc
--- /dev/null
+++ b/changelogs/asm_ausize.yml
@@ -0,0 +1,3 @@
+---
+bugfixes:
+  - "ASM disk's au_size setting not considered, except for initial diskgroup (#537)"
diff --git a/roles/orahost_meta/README.md b/roles/orahost_meta/README.md
index b8df26f3a..b6c54a62f 100644
--- a/roles/orahost_meta/README.md
+++ b/roles/orahost_meta/README.md
@@ -61,30 +61,44 @@ asm_diskgroups: []
 asm_diskgroups:
  - diskgroup: crs
    properties:
-     - {redundancy: normal, ausize: 4}
+     - {redundancy: normal}
    attributes:
-     - {name: 'compatible.rdbms', value: 11.2.0.4.0}
-     - {name: 'compatible.asm', value: 12.1.0.2.0}
+     - {name: compatible.asm, value: 12.1.0.2.0}
+     - {name: compatible.rdbms, value: 11.2.0.4.0}
+     - {name: au_size, value: 4m}
    disk:
      - {device: /dev/sdc, asmlabel: crs01}
      - {device: /dev/sdd, asmlabel: crs02}
      - {device: /dev/sde, asmlabel: crs03}
  - diskgroup: data
    properties:
-     - {redundancy: external, ausize: 4}
+     - {redundancy: external}
    attributes:
-     - {name: compatible.rdbms, value: 11.2.0.4.0}
      - {name: compatible.asm, value: 12.1.0.2.0}
+     - {name: compatible.rdbms, value: 11.2.0.4.0}
+     - {name: au_size, value: 4m}
    disk:
      - {device: /dev/sdf, asmlabel: data01}
  - diskgroup: fra
    properties:
-    - {redundancy: external, ausize: 4}
-  attributes:
-     - {name: compatible.rdbms, value: 11.2.0.4.0}
+    - {redundancy: external}
+   attributes:
      - {name: compatible.asm, value: 12.1.0.2.0}
+     - {name: compatible.rdbms, value: 11.2.0.4.0}
+     - {name: au_size, value: 4m}
    disk:
      - {device: /dev/sdg, asmlabel: fra01}
+
+# Defining ausize in `properties` is still supported for backward compatibility.
+# But, except for initial ASM diskgroup, it still won't be considered when creating the diskgroup, though.
+asm_diskgroups:
+ - diskgroup: crs
+   properties:
+     - {redundancy: normal, ausize: 4}
+   attributes:
+     - {name: compatible.asm, value: 12.1.0.2.0}
+     - {name: compatible.rdbms, value: 11.2.0.4.0}
+   ...
 ```
 
 ### asmadmin_group
diff --git a/roles/orahost_meta/defaults/main.yml b/roles/orahost_meta/defaults/main.yml
index dd31bd9bb..a497fb604 100644
--- a/roles/orahost_meta/defaults/main.yml
+++ b/roles/orahost_meta/defaults/main.yml
@@ -171,30 +171,44 @@ asm_diskgroups: []
 # asm_diskgroups:
 #  - diskgroup: crs
 #    properties:
-#      - {redundancy: normal, ausize: 4}
+#      - {redundancy: normal}
 #    attributes:
-#      - {name: 'compatible.rdbms', value: 11.2.0.4.0}
-#      - {name: 'compatible.asm', value: 12.1.0.2.0}
+#      - {name: compatible.asm, value: 12.1.0.2.0}
+#      - {name: compatible.rdbms, value: 11.2.0.4.0}
+#      - {name: au_size, value: 4m}
 #    disk:
 #      - {device: /dev/sdc, asmlabel: crs01}
 #      - {device: /dev/sdd, asmlabel: crs02}
 #      - {device: /dev/sde, asmlabel: crs03}
 #  - diskgroup: data
 #    properties:
-#      - {redundancy: external, ausize: 4}
+#      - {redundancy: external}
 #    attributes:
-#      - {name: compatible.rdbms, value: 11.2.0.4.0}
 #      - {name: compatible.asm, value: 12.1.0.2.0}
+#      - {name: compatible.rdbms, value: 11.2.0.4.0}
+#      - {name: au_size, value: 4m}
 #    disk:
 #      - {device: /dev/sdf, asmlabel: data01}
 #  - diskgroup: fra
 #    properties:
-#     - {redundancy: external, ausize: 4}
-#   attributes:
-#      - {name: compatible.rdbms, value: 11.2.0.4.0}
+#     - {redundancy: external}
+#    attributes:
 #      - {name: compatible.asm, value: 12.1.0.2.0}
+#      - {name: compatible.rdbms, value: 11.2.0.4.0}
+#      - {name: au_size, value: 4m}
 #    disk:
 #      - {device: /dev/sdg, asmlabel: fra01}
+#
+# # Defining ausize in `properties` is still supported for backward compatibility.
+# # But, except for initial ASM diskgroup, it still won't be considered when creating the diskgroup, though.
+# asm_diskgroups:
+#  - diskgroup: crs
+#    properties:
+#      - {redundancy: normal, ausize: 4}
+#    attributes:
+#      - {name: compatible.asm, value: 12.1.0.2.0}
+#      - {name: compatible.rdbms, value: 11.2.0.4.0}
+#    ...
 # @end
 
 # @var oracle_nr_bg_processes:description: Estimated number of background processes of an Oracle instance. Used to calculate kernel SEMMNS
diff --git a/roles/oraswgi_install/templates/grid-install.rsp.12.1.0.1.j2 b/roles/oraswgi_install/templates/grid-install.rsp.12.1.0.1.j2
index d654e6cc5..3517721b5 100644
--- a/roles/oraswgi_install/templates/grid-install.rsp.12.1.0.1.j2
+++ b/roles/oraswgi_install/templates/grid-install.rsp.12.1.0.1.j2
@@ -318,7 +318,15 @@ oracle.install.asm.diskGroup.redundancy={% for a in item.properties %}{{ a.redun
 # size unit is MB
 #
 #-------------------------------------------------------------------------------
-oracle.install.asm.diskGroup.AUSize={% for a in item.properties %}{{ a.ausize }}{% endfor %}
+oracle.install.asm.diskGroup.AUSize={%- if item.properties is defined
+      and item.properties | length > 0
+      and item.properties[0].ausize is defined -%}
+    {{ item.properties[0].ausize }}
+  {%- elif item.attributes is defined
+      and item.attributes | selectattr('name', 'equalto', 'au_size') is defined
+      and item.attributes | selectattr('name', 'equalto', 'au_size') | length > 0 -%}
+    {{ (item.attributes | selectattr('name', 'equalto', 'au_size'))[0]['value'] | regex_replace('[a-z]', '', ignorecase=true) }}
+  {%- endif %}
 
 #-------------------------------------------------------------------------------
 # List of disks to create a ASM DiskGroup
diff --git a/roles/oraswgi_install/templates/grid-install.rsp.12.1.0.2.j2 b/roles/oraswgi_install/templates/grid-install.rsp.12.1.0.2.j2
index cee47d8a9..d7b179ec0 100644
--- a/roles/oraswgi_install/templates/grid-install.rsp.12.1.0.2.j2
+++ b/roles/oraswgi_install/templates/grid-install.rsp.12.1.0.2.j2
@@ -319,7 +319,15 @@ oracle.install.asm.diskGroup.redundancy={% for a in item.properties %}{{ a.redun
 # size unit is MB
 #
 #-------------------------------------------------------------------------------
-oracle.install.asm.diskGroup.AUSize={% for a in item.properties %}{{ a.ausize }}{% endfor %}
+oracle.install.asm.diskGroup.AUSize={%- if item.properties is defined
+      and item.properties | length > 0
+      and item.properties[0].ausize is defined -%}
+    {{ item.properties[0].ausize }}
+  {%- elif item.attributes is defined
+      and item.attributes | selectattr('name', 'equalto', 'au_size') is defined
+      and item.attributes | selectattr('name', 'equalto', 'au_size') | length > 0 -%}
+    {{ (item.attributes | selectattr('name', 'equalto', 'au_size'))[0]['value'] | regex_replace('[a-z]', '', ignorecase=true) }}
+  {%- endif %}
 
 #-------------------------------------------------------------------------------
 # List of disks to create a ASM DiskGroup
diff --git a/roles/oraswgi_install/templates/grid-install.rsp.12.2.0.1.j2 b/roles/oraswgi_install/templates/grid-install.rsp.12.2.0.1.j2
index 664053504..1b0f5349e 100644
--- a/roles/oraswgi_install/templates/grid-install.rsp.12.2.0.1.j2
+++ b/roles/oraswgi_install/templates/grid-install.rsp.12.2.0.1.j2
@@ -413,7 +413,15 @@ oracle.install.asm.diskGroup.redundancy={% for a in item.properties %}{{ a.redun
 # size unit is MB
 #
 #-------------------------------------------------------------------------------
-oracle.install.asm.diskGroup.AUSize={% for a in item.properties %}{{ a.ausize }}{% endfor %}
+oracle.install.asm.diskGroup.AUSize={%- if item.properties is defined
+      and item.properties | length > 0
+      and item.properties[0].ausize is defined -%}
+    {{ item.properties[0].ausize }}
+  {%- elif item.attributes is defined
+      and item.attributes | selectattr('name', 'equalto', 'au_size') is defined
+      and item.attributes | selectattr('name', 'equalto', 'au_size') | length > 0 -%}
+    {{ (item.attributes | selectattr('name', 'equalto', 'au_size'))[0]['value'] | regex_replace('[a-z]', '', ignorecase=true) }}
+  {%- endif %}
 
 #-------------------------------------------------------------------------------
 # Failure Groups for the disk group
diff --git a/roles/oraswgi_install/templates/grid-install.rsp.18.3.0.0.j2 b/roles/oraswgi_install/templates/grid-install.rsp.18.3.0.0.j2
index bdb66fd0d..79f4ebe36 100644
--- a/roles/oraswgi_install/templates/grid-install.rsp.18.3.0.0.j2
+++ b/roles/oraswgi_install/templates/grid-install.rsp.18.3.0.0.j2
@@ -431,7 +431,15 @@ oracle.install.asm.diskGroup.redundancy={% for a in item.properties %}{{ a.redun
 # size unit is MB
 #
 #-------------------------------------------------------------------------------
-oracle.install.asm.diskGroup.AUSize={% for a in item.properties %}{{ a.ausize }}{% endfor %}
+oracle.install.asm.diskGroup.AUSize={%- if item.properties is defined
+      and item.properties | length > 0
+      and item.properties[0].ausize is defined -%}
+    {{ item.properties[0].ausize }}
+  {%- elif item.attributes is defined
+      and item.attributes | selectattr('name', 'equalto', 'au_size') is defined
+      and item.attributes | selectattr('name', 'equalto', 'au_size') | length > 0 -%}
+    {{ (item.attributes | selectattr('name', 'equalto', 'au_size'))[0]['value'] | regex_replace('[a-z]', '', ignorecase=true) }}
+  {%- endif %}
 
 #-------------------------------------------------------------------------------
 # Failure Groups for the disk group
diff --git a/roles/oraswgi_install/templates/grid-install.rsp.19.3.0.0.j2 b/roles/oraswgi_install/templates/grid-install.rsp.19.3.0.0.j2
index 9f7fb778c..7db833b95 100644
--- a/roles/oraswgi_install/templates/grid-install.rsp.19.3.0.0.j2
+++ b/roles/oraswgi_install/templates/grid-install.rsp.19.3.0.0.j2
@@ -419,7 +419,15 @@ oracle.install.asm.diskGroup.redundancy={% for a in item.properties %}{{ a.redun
 # size unit is MB
 #
 #-------------------------------------------------------------------------------
-oracle.install.asm.diskGroup.AUSize={% for a in item.properties %}{{ a.ausize }}{% endfor %}
+oracle.install.asm.diskGroup.AUSize={%- if item.properties is defined
+      and item.properties | length > 0
+      and item.properties[0].ausize is defined -%}
+    {{ item.properties[0].ausize }}
+  {%- elif item.attributes is defined
+      and item.attributes | selectattr('name', 'equalto', 'au_size') is defined
+      and item.attributes | selectattr('name', 'equalto', 'au_size') | length > 0 -%}
+    {{ (item.attributes | selectattr('name', 'equalto', 'au_size'))[0]['value'] | regex_replace('[a-z]', '', ignorecase=true) }}
+  {%- endif %}
 
 #-------------------------------------------------------------------------------
 # Failure Groups for the disk group
diff --git a/roles/oraswgi_install/templates/grid-install.rsp.21.3.0.0.j2 b/roles/oraswgi_install/templates/grid-install.rsp.21.3.0.0.j2
index d3607e59c..515608518 100644
--- a/roles/oraswgi_install/templates/grid-install.rsp.21.3.0.0.j2
+++ b/roles/oraswgi_install/templates/grid-install.rsp.21.3.0.0.j2
@@ -403,7 +403,15 @@ oracle.install.asm.diskGroup.redundancy={% for a in item.properties %}{{ a.redun
 # size unit is MB
 #
 #-------------------------------------------------------------------------------
-oracle.install.asm.diskGroup.AUSize={% for a in item.properties %}{{ a.ausize }}{% endfor %}
+oracle.install.asm.diskGroup.AUSize={%- if item.properties is defined
+      and item.properties | length > 0
+      and item.properties[0].ausize is defined -%}
+    {{ item.properties[0].ausize }}
+  {%- elif item.attributes is defined
+      and item.attributes | selectattr('name', 'equalto', 'au_size') is defined
+      and item.attributes | selectattr('name', 'equalto', 'au_size') | length > 0 -%}
+    {{ (item.attributes | selectattr('name', 'equalto', 'au_size'))[0]['value'] | regex_replace('[a-z]', '', ignorecase=true) }}
+  {%- endif %}
 
 #-------------------------------------------------------------------------------
 # Failure Groups for the disk group