Comment 20 for bug 37639

I have a similar machine which doesn't have any IDE hard drives, only an IDE CD-ROM drive and 3 SCSI drives connected to a Adaptec AHA-2940U2/U2W in hardware RAID5 configuration.

I think I'm experiencing the same problem.

Ubuntu 5.10 installer crashes on that machine (see Bug #46420).

Dapper daily install CD (alternative install) from yesterday (2006-05-29) installs fine on this machine, but when I boot into the freshly installed system, I get the error:

"Uncompressing Linux... Ok, booting the kernel.
[4294706.598000] iop0: device already claimed
[4294706.652000] iop0: DMA / IO allocation for I2O controller failed
ALERT! /dev/i2o/hda3 does not exist. Dropping to a shell!"

The grub command line for the kernel is:

kernel /vmlinuz-2.6.15-23-386 root=/dev/i2o/hda3 ro quiet splash

Grepping in /proc/modules reveals that the loaded i2o modules are dpt_i2o and i2o_core:

i2o_core 41112 0 - Live 0xe086d000
dpt_i2o 33308 0 - Live 0xe08e9000
scsi_mod 139496 4 sd_mod,dpt_i2o,aic7xxx,scsi_transport_spi2, Live 0xe08bb000

I've tried the workaround suggested by James Remnant and it works, the system continues booting:

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
ln -s /dev/sda5 /dev/i2o/hda5
exit
 * Reading files needed to boot... [ ok ]
 * Preparing restricted drivers... [ ok ]
 * Starting basic networking... [ ok ]
 * Starting kernel event manager... [ ok ]
 * Loading hardware drivers... [ ok ]
...

So the problem is indeed with inconsistency in device naming between drivers (/dev/sda by dpt_i2o and /dev/i2o/hda by the other one).