dma/io allocation for i2o controller failed

In order to work around this problem you need to go through these steps:

1) At the busybox type:

mkdir /dev/i2o
ln -s /dev/sda /dev/i2o/hda
ln -s /dev/sda1 /dev/i2o/hda1
ln -s /dev/sda2 /dev/i2o/hda2
ln -s /dev/sda3 /dev/i2o/hda3
(go on until you linked all your devices)
exit

2) Now your server should continue the boot process; as soon as you get the prompt fix the problem blacklisting the module in the initrd image: for example:

mkdir initrd
cd initrd
zcat /boot/initrd.img-2.6.15-28-server | cpio -ivdm
echo "blacklist dpt_i2o" >> etc/modprobe.d/blacklist
find . | cpio --quiet -o -H newc | gzip -9 > /boot/initrd.img-2.6.15-28-server