DSM-G600, DNS-3xx and NSA-220 Hack Forum

Hello,

i've searched the forum extensively, but i have not found an answer to an issue i'm having.  i'm hoping that does not mean it is impossible with the DNS-323..

i have ffp 0.5 installed on my DNS-323.  it's set up in RAID 1.

i have a 750GB hard drive seated in an external case that has a USB connection on it.  i've formatted this drive with 2 partitions with Mac Extended (Journaled) filesystem.  the partition type was GUID (i want to be able to boot of the disk in case of a failure).

i'm hoping to be able to connect this to the USB port on my DNS-323 and mount it.  however, i have had no luck doing so.  when i plug it in, i see this from dmesg:

usb-storage: device found at 13
usb-storage: waiting for device to settle before scanning
  Vendor: Ext Hard  Model:  Disk             Rev:     
  Type:   Direct-Access                      ANSI SCSI revision: 04
sdc: Spinning up disk....ready
SCSI device sdc: 1465149168 512-byte hdwr sectors (750156 MB)
sdc: assuming drive cache: write through
SCSI device sdc: 1465149168 512-byte hdwr sectors (750156 MB)
sdc: assuming drive cache: write through
sdc: sdc1
Attached scsi disk sdc at scsi7, channel 0, id 0, lun 0
Attached scsi generic sg2 at scsi7, channel 0, id 0, lun 0,  type 0
usb-storage: device scan complete

then i ran fdisk -l:

   Device Boot      Start         End      Blocks  Id System
/dev/sdc1               1       91202   732574583+ ee EFI GPT

so that's the first thing that seems strange.  only seems to see it as a single partition, and as a type i'm not familiar with. 

i've tried to mount it with ever parameter to mount i can think of but always get an error (either "invalid argument" or "no such device"

is there any way to mount this drive as formatted via the DNS-323?  if not, is there a format that will work for both a Mac and the DNS-323?

i really appreciate any help on this one!

Matt