disable multipath for longhorn volume

roles/k3s/files/multipath.conf

@@ -0,0 +1,6 @@
+defaults {
+    user_friendly_names yes
+}
+blacklist {
+    devnode "^sd[a-z0-9]+"
+}

roles/k3s/handlers/main.yml

@@ -1,2 +1,7 @@
+- name: Restart multipathd
+  service:
+    name: multipathd
+    state: restarted
+
 - name: reboot
   reboot:

roles/k3s/tasks/main.yml

@@ -1,7 +1,14 @@
 - name: Install required packages
   apt:
     name:
-      - open-iscsi
-      - nfs-common
+      - open-iscsi # required by longhorn
+      - nfs-common # required for nfs support
+
+# https://longhorn.io/kb/troubleshooting-volume-with-multipath/
+- name: Disable multipath (for longhorn volumes)
+  copy:
+    src: multipath.conf
+    dest: /etc/multipath.conf
+  notify: Restart multipathd
 
 - include_tasks: '{{ platform }}.yml'