Comment 6 for bug 431103

Ok, prepare for long windedness.

I've tried to determine if the regression shown here was due to a kernel
change (including ramdisk) or a user space change. To do that, I ran
several different combinations of root and initrd and checked console
output.

aliases:
- ec2-krd = aki-a71cf9ce / aki-9c04e4f5
  ec2-vmlinuz-2.6.21.7-2.fc8xen.i386
  ec2-initrd-2.6.21.7-2.fc8xen.i386
- karmic-krd = aki-841efeed / ari-9a1efef3
  ubuntu-kernel-2.6.31-300-ec2-xen-i386-20090910-test-02
  ubuntu-ramdisk-2.6.31-300-ec2-xen-i386-20090910-test-02.manifest.xml
- intrepid-krd = aki-714daa18 / ari-7e4daa17
  vmlinuz-2.6.27-23-xen-i386
  initrd.img-2.6.27-23-xen-i386
- alpha5 = ami-3520c05c
  karmic-i386-alpha5.manifest.xml
- alpha5.1 = ami-a40fefcd
  karmic-i386-alpha5.1.manifest.xml
- alpha6 = ami-fa658593
  karmic-i386-alpha6.manifest.xml

- Note, aki-9c04e4f5 / ari-9e04e4f7 == aki-841efeed / ari-9a1efef3
  I simply re-published the same manifest in a different bucket generating
  the different numbers

root_________| kern/rd | instance | result
alpha5_______| amazon-ec2 | i-c374a0ab | Yes : init messages get to console
alpha5______ | karmic-krd | i-ab73a7c3 | No : no console output past kernel
alpha5.1_____| karmic-krd | i-9573a7fd | No : no console output past kernel
alpha6_______| amazon-ec2 | i-0778ac6f | Yes : init messages ("Deactivating swap", "init:")
alpha6_______| karmic-krd | i-c726f2af | No : no console output past kernel

Note, the amazon-ec2 kernels dont completly boot with our user space, so
the output isn't as clear as you'd like, but you do see output from the
init process and sysvinit.

Its not completely straightforward, but I believe that the above shows a regression in the kernel/initrd rather than in userspace init or general makeup of image.