Howtoforge posted a tutorial about creating an NFS-like stroage server with GlusterFS on Ubuntu

This tutorial shows how to set up a standalone storage server on Ubuntu 11.10. Instead of NFS, I will use GlusterFS here. The client system will be able to access the storage as if it was a local filesystem. GlusterFS is a clustered file-system capable of scaling to several peta-bytes. It aggregates various storage bricks over Infiniband RDMA or TCP/IP interconnect into one large parallel network file system. Storage bricks can be made of any commodity hardware such as x86_64 servers with SATA-II RAID and Infiniband HBA.

  Creating An NFS-Like Standalone Storage Server With GlusterFS 3.2.x On Ubuntu 11.10