gistfile1.txt

1.9.3-p484 :082 > a = [{"persistent"=>true,"format_type"=>"raw","name"=>"fog-492279386986572","capacity"=>"10G","allocation"=>"0G","id"=>"","pool_name"=>"VolGroup00"}]
 => [{"persistent"=>true, "format_type"=>"raw", "name"=>"fog-492279386986572", "capacity"=>"10G", "allocation"=>"0G", "id"=>"", "pool_name"=>"VolGroup00"}] 
1.9.3-p484 :083 > a.map! do |volume|
1.9.3-p484 :084 >       if volume.instance_of?(Hash) && volume[:id].present?
1.9.3-p484 :085?>         volume
1.9.3-p484 :086?>       elsif volume.instance_of?(Hash)
1.9.3-p484 :087?>         volume.reject! { |k, v| k == :id }
1.9.3-p484 :088?>       end
1.9.3-p484 :089?>   end
 => [nil] 
 
 Should be: 
  => [{"persistent"=>true, "format_type"=>"raw", "name"=>"fog-492279386986572", "capacity"=>"10G", "allocation"=>"0G", "pool_name"=>"VolGroup00"}]