[CentOS] Large disk support

I have a 3.5 TB RAID 5 Array through a 3ware 9590SE 8 port card, and am 
running into what seems like quite a lot of problems trying to get the system 
installed correctly.  The system is a running dual Opterons with 2 GB of RAM, 
and I'm attempting to install through the x86_64 ServerCD.

First, grub refuses to install on the disk, as it's too large.  I can get 
around this though by booting Fedora Core 6 in rescue mode and running grub, 
as it can deal with the disk size correctly.  This might only be working when 
I attempt installs that don't utilize as much of the array as possible though 
(100 MB /boot, 2GB swap, 10Gb /, the rest left unallocated).

Secondly, there seems to be a problem using msdos disk labels with large 
partitions, and I can't seem to find any solutions to this in the manuals or 
on the net.  GPT labels are offered as a solution to this but only for 
Itanium systems.

Am I missing some obvious solution to this?  Are there some best practices for 
dealing with large disks anyone can share that may save me problems now or 
later?  I'm open to suggestions, as all I've encountered so far are problems.

-- 
- Kevan Benson
- A-1 Networks