>A) Can CentOS 6 handle that many JBOD disks in one system? is my upper >size too big and I should plan for 2 or more servers? What happens with >the device names when you've gone past /dev/sdz ? Dev names double, sdaa etc. >B) What is the status of large file system support in CentOS 6? I know XFS > is frequently mentioned with such systems, but I/we have zero experience >with it, its never been natively supported in EL up to 5, anyways. My use of XFS has been with great success in 5.x. I have never scaled that large though. >C) Is GFS suitable for this, or is it strictly for clustered storage systems? Unless you plan on mounting the fs by more than one server at once, I most certainly would not add that layer of complexity, its also slower. >D) anything important I've neglected? If I understand, it's not your only backup system, so I don't think it's that critical, but the rebuild time on each array versus the degraded IO capacity and its impact on serving content would be something interesting. Do you plan on making hotspares available? That many discs will likely have a higher rate of failure... What kind of discs and controllers do you intend on using? jlc