External RAID, GFS

Hi,

I have an external SCSI RAID disk which I'd like to share between two
machines (so that both can access it simulataneously). Am I right in
thinking that I need GFS for this? I haven't been able to find much
documentation on GFS, but I assume it's just a case of compiling it into
the kernel (if it's not already) then using mount, mkfs etc as I would for
an ext2 partition?

Thanks,
Kermit
.