diff --git a/deployment/puppet/osnailyfacter/lib/puppet/parser/functions/get_disks_list_by_role.rb b/deployment/puppet/osnailyfacter/lib/puppet/parser/functions/get_disks_list_by_role.rb
index 5fe84bfaf1..015dbb1119 100644
--- a/deployment/puppet/osnailyfacter/lib/puppet/parser/functions/get_disks_list_by_role.rb
+++ b/deployment/puppet/osnailyfacter/lib/puppet/parser/functions/get_disks_list_by_role.rb
@@ -7,13 +7,13 @@ EOS
   ) do |args|
     errmsg = "get_disks_list_by_role($node_volumes, 'cinder')"
     disks_metadata, role = args
-    raise(Puppet::ParseError, "#{errmsg}: 1st argument should be an array") if !disks_metadata.is_a?(Array)
-    raise(Puppet::ParseError, "#{errmsg}: 2nd argument should be node role") if !role.is_a?(String)
+    raise(Puppet::ParseError, "#{errmsg}: 1st argument should be an array") unless disks_metadata.is_a?(Array)
+    raise(Puppet::ParseError, "#{errmsg}: 2nd argument should be node role") unless role.is_a?(String)
     disks = Array.new
     disks_metadata.each do |disk|
-      if not disk['volumes'].nil? and not disk['volumes'].empty?
+      unless disk['volumes'].nil? and disk['volumes'].empty?
         disk['volumes'].each do |volume|
-          if not volume['vg'].nil? and volume['vg'] == role and not volume['size'].nil? and volume['size'] != 0
+          unless volume['vg'].nil? or volume['vg'] != role or volume['size'].nil? or volume['size'] == 0
             disks << '/dev/' + disk['name']
             break
           end