On Mon, Nov 12, 2012 at 6:01 AM, Fredrik Jonson<fredrik@jonson.org>  wrote:
William A. Mahaffey III wrote:
  .... I am brand new to Debian [...] [I have a box that] has 2 other drives
  on it, 1 IDE 500 GB Seagate, 1 SATA 500 GB WD. Those are both use ext3
  filesystem, left over from the CentOS 5.7 that I was running on that box
  before the root drive died. I tried to mount those drives as ext3 drives&  I
  get the following:
  # mount -t ext3    /dev/ad0s1  /mnt
  mount: /dev/ad0s1: No such device
Are you sure that /dev/ad0s1 is your file system? I'd expect a PATA drive to
show up named /dev/hda or /dev/hdb and partitions named /dev/hda1 etc. Likewise
SATA drives are normally named /dev/sda with partitions named /dev/sda1 etc.
Are you running debian-kfreebsd?
What does dmesg say about the disks? What about 'cfdisk -P s /dev/ad0'?
With a Linux kernel, BSD slices are sd partitions.