[arch-general] Why Is My RAID Installing Failing?

[Alexander Duscheleit]

On Wed, 13 Jan 2010 22:58:34 +0100
Dieter Plaetinck <dieter at plaetinck.be> wrote:

> On Wed, 13 Jan 2010 14:22:30 -0500
> Carlos Williams <carloswill at gmail.com> wrote:
> 
> > On Wed, Jan 13, 2010 at 1:57 PM, Alexander Duscheleit
> > <jinks at archlinux.us> wrote:
> > > I still think /arch/setup *should* generate this file itself if it
> > > detects software raids in use for the target. The wiki even seems
> > > to suggest, that it does.
> > >
> > > Could some releng shine light on this, please?
> > 
> > I completely agree. The Wiki suggests that it's as simple as self
> > generating if I follow the steps and it clearly is not. I became so
> > frustrated I almost abandoned Arch. I hope this gets fixed in a soon
> > future release of Arch.
> 
> AIF has no support for softraid.
> It does make sure menu.lst, fstab etc are updated automagically but
> only for dm_crypt/lvm/"normal" setups.

That answers my question.
The problem in this specific case is, that you have to sidestep the
installer. Before running setup your target system isn't mounted, and
after it is too late to put the file in place for mkinitcpio.

Would it be possible to just generate the relevant mdadm.conf during
the configure stage without providing further additional support?
People are used to run installation steps in sequence so this would
eliminate on source of (apparently frustrating) user error.

A quick look at AIF's source suggest prefill_configs () as proper place.
I'm not certain, how AIF identifies used block devices, but something
like this would probably suffice:

if md[0-9] in $BLOCKDEVICES ->
      mdadm --detail --scan >> ${var_TARGET_DIR}/etc/mdadm.conf

> 
> If the official installation guide states otherwise, we should fix
> that. please point me to the mistake/file a ticket.
> If community-maintained documentation is incorrect, fix it yourself.

The official istall guide specifically states that you are on your own
with softraid. The raid/lvm/etc wiki article is a bit twisted in it's
mix-and-match of methods, I shall have another look if I can squeeze
the relevant information in there.

> 
> Patches to support softraid are always welcome.  Things don't get
> improved by merely hoping for it.
> http://bugs.archlinux.org/task/14149

WONTFIX! This is already far too easy :)

> 
> Dieter

Jinks