From mboxrd@z Thu Jan  1 00:00:00 1970
From: Piergiorgio Sartor <piergiorgio.sartor@nexgo.de>
Subject: Re: (boot time consequences of) Linux mdadm superblock question.
Date: Fri, 19 Feb 2010 10:16:19 +0100
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To: Neil Brown <neilb@suse.de>, Daniel Reurich <daniel@centurion.net.nz>, linux-raid <linux-raid@vger.kernel.org>, 567468@bugs.debian.org
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Hi,

> True. You'd have to update the superblock UUID right after creation
> of the filesystem. That doesn't sound like a robust strategy to
> making mdadm.conf optional.

it seems that, with "dracut", "mdadm.conf" is optional.

There is the kernel boot paramenter "rd_NO_MDADMCONF",
which forces "dracut" to do not use the "mdadm.conf" in
the initramfs image.

This seems to work also if / is on mdX.

I just tried it, and it was running fine. I did not check
the details, i.e. I've no proof "dracut" was not cheating.

My impression is that it uses the "mdadm -I" functionality.

There are other interesting kernel boot options, like:

rd_MD_UUID=<md uuid>

bye,

-- 

piergiorgio