Install 5.3 - Getting mountroot> prompt

[Scott]

  >   I will really appreciate it of someone can
  >   help
  >   me out.
  >
  >   I am installing 5.3 on a dual p3 server. I
  >   have
  >   two 160 gig Seagate IDE drives on the first
  >   IDE
  >   connector, and a CD rom on the 2nd IDE
  >   connector.
  >   I have reinstalled several times with
  >   different
  >   drive configurations and keep getting stuck
  >   at
  >   the same place.
  >
  >   At boot, the normal countdown loader comes
  >   up and
  >   it begins to boot. The boot message gets to
  >   this
  >   drive section below and then stops at a
  >   "mountroot>" prompt.
  >
  >   Begin copy .......
  >
  >   ad0: 152627MB <ST3160023A/8.01>
  >   [310101/16/63]
  >   at ata0-master UDMA66
  >   ad1: 152627MB <ST3160023A/8.01>
  >   [310101/16/63]
  >   at ata0-master UDMA66
  >   acd0: <CDU5211/YYS2> at ata1-master PIO4
  >
  >   Manual root filesystem specification:
  >   <fstype>:<device> Mount <device> using
  >   filesystem
  >   <fstype>
  >   eg. usf:da0s1a
  >   ? List valid desk boot devices
  >   <empty line> Abort manual input
  >
  >   mountroot>
  >
  >   ............ End copy
  >
  >   If I type: ufs:ad0s1a
  >   at that "mountroot>"
  >   prompt, it will boot normally and as far as
  >   I can
  >   tell, all is working like I would expect. I
  >   suspected this may have something to do
  >   with my
  >   fstab but it looks normal to me:
  >
  >   /dev/ad0s1b  none      swap  sw  0 0
  >   /dev/ad1s1b  none      swap  sw  0 0
  >   /dev/ad0s1a  /            ufs     rw 1 1
  >   /dev/ad1s1d  /backup  ufs      rw 2 2
  >   /dev/ad0s1d  /tmp       ufs      rw  2 2
  >   /dev/acd0     /cdrom    cd9660  ro,noauto
  >   0 0
  >
  >   Please let me know if I can provide more
  >   information that will help you help me know
  >   what to do to get it to automatically go on
  >   to boot ad0s1a.

One more thing I just found out, if it helps. If I just
let it boot, I get to the mountroot> prompt as above
and can boot the system after entering the location
of the root partition.

If I chose option 2 and boot with ACPI off, the drives 
are not found and I get:
FAILURE - ATA_IDENTIFY timed out
errors on both the master and slave drives. At that point, 
I get the mountroot> prompt again, but of course can 
not mount the root partition.

So now I'm wondering why if I boot with ACPI on, the 
drives are found, but root doesn't boot. With ACPI off, 
the drives are not even found. I hope that helps 
someone tell me where to look.

5.2.1 was booting off this same drive normally before 
I replaced it with 5.3.

Thanks,
Scott