From: Wols Lists <antlists@youngman.org.uk>
To: Geoff Back <geoff@demonlair.co.uk>, Song Liu <song@kernel.org>
Cc: linux-raid@vger.kernel.org
Subject: Re: Patch to fix boot from RAID-1 partitioned arrays
Date: Wed, 12 May 2021 12:07:51 +0100 [thread overview]
Message-ID: <609BB707.5030505@youngman.org.uk> (raw)
In-Reply-To: <d9e1f759-3a11-1d63-f16c-8b999190c633@demonlair.co.uk>
On 12/05/21 09:41, Geoff Back wrote:
> Good morning.
>
> I have had problems in all recent kernels with booting directly from MD
> RAID-1 partitioned arrays (i.e. without using an initrd).
> All the usual requirements - building md and raid1 into the kernel,
> correct partition types, etc - are correct.
>
> Deep investigation has led me to conclude that the issue is caused by
> boot-time assembly of the array not reading the partition table, meaning
> that the partitions are not visible and cannot be mounted as root
> filesystem.
The other thing is, what superblock are you using? Sounds to me like
you're trying to use an unsupported and bit-rotting option.
Standard procedure today is that you MUST run mdadm to assemble the
array, which means having a functioning user-space, which I believe
means initrd or some such to create the array before you can make it root.
You saying that you need to read the partition table even when you have
a successfully assembled array makes me think something is weird here ...
If you can give us a bit more detail, we can then decide whether what
you're doing is supposed to work or not.
Basically, as I understand what you're doing, you need a 0.9
(unsupported) superblock, and also (unsupported) in-kernel raid assembly.
Cheers,
Wol
next prev parent reply other threads:[~2021-05-12 9:47 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-12 8:41 Patch to fix boot from RAID-1 partitioned arrays Geoff Back
2021-05-12 9:11 ` Geoff Back
2021-05-12 11:07 ` Wols Lists [this message]
2021-05-12 10:56 ` Geoff Back
2021-05-12 22:18 ` J. Brian Kelley
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