There are a few distributed FS into the Linux Kernel IIRC, but I haven't played with them.  If you want a centralized solution you could setup a RAID5 on the server using mdadm, and share the files with NFS or NBD (network block device).

I wonder if you could create a RAID5 with NBDs, that would be distributed.  Anyway check the all the FS in the kernel, they are there for a reason.