Comment 6 for bug 1361842

Ignoring the raid label is the entire problem - that is what the broken
dmraid script is already doing.

Fundamentally, if /dev/sda has a valid RAID label then it *MUST* be setup
and accessed through the dmraid device and *NEVER* via /dev/sda.

Otherwise the installer will see a disc that is too big and it will destroy
the RAID label at the end of the disc, then the system will not boot.

The work around solution is to manually start dmraid before partitioning in
the installer, then the system will remain bootable, the OS partition will
not overlap the RAID label, etc. But once booted it still accesses through
/dev/sda and there is a risk that a partitioning tool will again blindly
destroy the RAID label.

I can't see how it would ever be correct for boot scripts to ignore a RAID
label, if there is a label, the drive is part of a RAID set and it must be
activated through dmraid. A single disc RAID still has a label, and still
needs to be accessed through device mapper.

FWIW, RHEL gets this right and sets up dmraid on this disc.

Jason

On Tue, Oct 28, 2014 at 6:32 PM, Phillip Susi <email address hidden> wrote:

> That is one broken firmware if it does not present plain, non raid
> disks. You should be able to work around it by booting the installer
> with the nodmraid option. This will have Ubuntu ignore the raid
> signatures and just use the drive normally.
>
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> https://bugs.launchpad.net/bugs/1361842
>
> Title:
> dmraid does not start on boot for single disk RAID0
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