SoftRAID for Windows XP and Ubuntu (10.04)

In order to use a RAID (0,1) array to install both Windows XP and Ubuntu, a SoftRAID must be used.

First step
Size the hard drive to have the same number of visible sector, using hdparm.
This can be accomplish from a linux host (I use System Rescue CD for this kind of activities).

Es.
hdparm -N /dev/sda
output: visible sectors / total sectors

hdparm -N /dev/sdb
output: visible sectors / total sectors

Then set the size of the biggest to the minimum size between the 2 using the command:

hdparm -NpMINIMUM /dev/sdX

For example:
hdparm -N /dev/sda
output: 488397168/488397168

hdparm -N /dev/sdb
output: 625140335/625142448

hdparm -Np488397168 /dev/sdb

Then reboot!!!

Second step
Partition the array to prepare the space for the operating systems.
For this I use GParted in System Rescue CD, but I noticed that the array may not have been detected automatically, so I start GParted from the command line, passing as argument the array device

Es.
gparted /dev/md0


Third step
Install Windows

Fourth step
Install Ubuntu. You may need to modfy the kernel parameter passed in at boot to disable HPA. Otherwise it will result in a RAID not recognized and you will have to power off the PC in order to recover it.
In Ubuntu 10.04 I have added the parameter libata.ignore_hpa=0 to the APPEND section of PXELinux for the installer.