From: NeilBrown <neilb@suse.de>
To: Bostjan Skufca <bostjan@a2o.si>
Cc: linux-raid@vger.kernel.org
Subject: Re: Boot option raid=parttitionable and autodetection
Date: Thu, 11 Sep 2014 10:02:11 +1000 [thread overview]
Message-ID: <20140911100211.6984024a@notabene.brown> (raw)
In-Reply-To: <CAEp_DRBuccHOzkrJe8UKP1bKLdk_GM1TB8rqB_7_9w-fgdUZ0g@mail.gmail.com>
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On Thu, 11 Sep 2014 01:31:13 +0200 Bostjan Skufca <bostjan@a2o.si> wrote:
> Hi all,
>
> does kernel boot time parameter raid=partitionable ofer any additional
> feature over not using it at all?
>
> Besides changing autodetected device names from /dev/mdX to /dev/md_dX
> I currently can not see any other difference, save lilo being unable
> to work with them.
You have identified the one singular thing which that parameter does. It
does nothing else.
>
> Normal raid devices can be partitioned without hassle,
This was not true when that parameter was added. It is true now.
So best to ignore that parameter.
> unfortunately
> in-kernel autodetection of nested raid arrays does not work (talking
> about raid0 over raid1 here, not raid10), but that is more or less
> understandable.
I discourage use of in-kernel autodetection. Use mdadm from an initrd
instead.
>
>
> Another quick question:
> What is the status of in-kernel autodetection vs initramfs based one?
initramfs based is preferred at least by me.
> As I could gather from various sites it seems initramfs is preferable,
> but what does that mean for in-kernel detection? Is it slowly being
> phased out?
Not it isn't being phase out, but it is not being enhanced at all. Some new
features only work with v1.x metadata and that cannot be used with in-kernel
autodetection.
NeilBrown
>
> Tnx for info,
> b.
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prev parent reply other threads:[~2014-09-11 0:02 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-09-10 23:31 Boot option raid=parttitionable and autodetection Bostjan Skufca
2014-09-11 0:02 ` NeilBrown [this message]
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