Linux guest/OSX host with createrawvmdk: "unrecognized partition table"

[Eric Drechsel]

I have a MBP with rEFIt and a working Ubuntu Jaunty amd64 on partition 3, with partition 4 swap. I request a vmdk file to provide guest access to these physical partitions:

chgrp admin /dev/disk0s3 /dev/disk0s4 
chmod g+w /dev/disk0s3 /dev/disk0s4 
cd ~/Library/VirtualBox/Machines/
VBoxManage internalcommands createrawvmdk -filename rawdisk.vmdk -rawdisk /dev/disk0 -partitions 3,4 -register

Afterwards, grub (on partition 3) runs, and I am able to see and access the partitions from grub (using cat, etc). Ubuntu initramfs, however, gives the error "unrecognized partition table", and doesn't register any partitions.

Any ideas for what could be causing this behavior?

Some context is in the last few comments on #1461, however that bug is fixed.