openqa/server: ignore_errors in createhdds

it's not really fatal when it fails (except on first deployment)
and nothing else later depends on it, so we can go ahead and
continue the run even if it fails

roles/openqa/server/tasks/main.yml

@@ -126,9 +126,14 @@
   changed_when: "1 != 1"
   always_run: true
 
+# createhdds is kinda fragile and failure is not really fatal on an
+# existing deployment (just means we have an outdated disk image), so
+# we ignore_errors so the rest of the playbook will complete even if
+# it fails
 - name: Create hard disk images (this may take a long time!)
   command: "/etc/cron.daily/createhdds"
   when: "diskcheck.rc > 0"
+  ignore_errors: yes
 
 - name: Create exports file
   copy: src=exports dest=/etc/exports.d/openqa.exports owner=root group=root mode=0644