внимательно читал FAQ на GFS, и ни слова не нашёл про возможность использования "локальных дисков машин в кластере, как составных элементов общей файловой системы.".13. What hardware do I need to run one of these "clusters"?
It depends on which components you need to use. For a basic cluster, all you need is two or more computers and a network between them. If you want to use GFS, you'll need shared storage.
15. Do I really need shared storage?
The point of using GFS and CLVM is that you have storage you want to share between machines concurrently. Without shared storage, you have a local filesystem and lvm2, neither of which need the cluster infrastructure.