My group currently has two largish storage servers, both NAS running debian linux. The first is an all-in-one 24-disk (SATA) server that is several years old. We have two hardware RAIDS set up on it with LVM over those. The second server is 64 disks divided over 4 enclosures, each a hardware RAID 6, connected via external SAS. We use XFS with LVM over that to create 100TB useable storage. All of this works pretty well, but we are outgrowing these systems. Having build two such servers and still growing, we want to build something that allows us more flexibility in terms of future growth, backup options, that behaves better under disk failure (checking the larger filesystem can take a day or more), and can stand up in a heavily concurrent environment (think small computer cluster). We do not have system administration support, so we administer all of this ourselves (we are a genomics lab).
So, what we seek is a relatively low-cost, acceptable performance storage solution that will allow future growth and flexible configuration (think ZFS with different pools having different operating characteristics). We are probably outside the realm of a single NAS. We have been thinking about a combination of ZFS (on openindiana, for example) or btrfs per server with glusterfs running on top of that if we do it ourselves. What we are weighing that against is simply biting the bullet and investing in Isilon or 3Par storage solutions.
Any suggestions or experiences are appreciated.