After the installation of debian lenny on my i2o controller (via manual bootloader installation), the system halts:

iop0: DMA / IO allocation for I2O controller failed

The problem is that the dpt_i2o module is loaded before i2o_core, so that i2o_core module cannot allocate the i2o controller.

The simplest solution is to to blacklist the dpt_i2o module, so that module is not loaded at startup and i2o_core can successfull allocate the i2o controller.

For lilo, add this in your /etc/lilo.conf:

image=/vmlinuz
        ...
        append="blacklist=dpt_i2o"

Do not forget to run “lilo” afterwards.

For grub, you must add the the following kernel parameter:

...
kernel /vmlinuz ro root=/dev/i2o/hda1 blacklist=dpt_i2o

I do not use grub, so please correct me if the param is somehow wrong.