In the Dell PowerEdge SC1435 servers delivered July 2008,
there are several BIOS settings that need to be frobbed on setup.

in the setup screen at F2:
- CPU -> Virtualization Technology: on
- Boot Sequence: disable NIC
- Integrated Devices -> Embedded Gb NIC: turn off PXE

in the setup screen for remote management, at Ctrl-E:
- IP is (main IP) =~ s/18.181.0/10.5.128/
  e.g. 10.5.128.221 for citadel-station == 18.181.0.221
- netmask is 255.255.0.0

These settings are reflected in the basic screen of xvm-host-2 and the
remote-management screen of xvm-host-1.  At time of writing, the basic
settings on xvm-host-1 may differ, and the remote-management settings
on xvm-host-2 are disabled.  xvm-host-3 has IPMI-over-LAN enabled in
the Ctrl-E screen.  xvm-host-4 remains unconfigured.


In the debian installer:
 - 500M for /boot in raid1 of sda1, sdb1
 - rest for LVM in raid1 of sda2, sdb2
  - 50G /
  - 25G swap
 - install a vanilla kernel, not xen;
   will install xen hypervisor from backports in our later custom install.