From: NeilBrown <neilb@suse.de>
To: CoolCold <coolthecold@gmail.com>
Cc: Larkin Lowrey <llowrey@nuclearwinter.com>,
linux-raid <linux-raid@vger.kernel.org>
Subject: Re: Kernel oops adding bitmap
Date: Thu, 22 Mar 2012 07:03:08 +1100 [thread overview]
Message-ID: <20120322070308.2233d1dd@notabene.brown> (raw)
In-Reply-To: <CAGqmV7qgQUxndmFzAU=cx3stQryOYRSRGPb_1HX9Nw9Ludot-A@mail.gmail.com>
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On Wed, 21 Mar 2012 17:21:55 +0400 CoolCold <coolthecold@gmail.com> wrote:
> Btw, was interested in, where bitmap will be placed when adding it on
> live array? I.e. as it requires some diskspace, we should provide some
> free space, but where it can be taken from if array is already created
> and used by, say filesystem?
For 0.90 metadata there is 60K of unused space after the superblock. The
bitmap is stored there.
For 1.x, the metadata stores a data_offset and data_size. All array data is
in that range. Anything out side there is available for mdadm to use.
When mdadm creates an array it reserves enough space for bitmap and possible
other uses.
NeilBrown
>
> On Tue, Mar 20, 2012 at 1:40 AM, Larkin Lowrey
> <llowrey@nuclearwinter.com> wrote:
> > On 3/19/2012 4:32 PM, NeilBrown wrote:
> >> On Mon, 19 Mar 2012 11:44:45 -0500 Larkin Lowrey
> > <llowrey@nuclearwinter.com>
> >> wrote:
> >>
> >>> The following command oopsed.
> >>>
> >>> mdadm -G --bitmap=internal /dev/md0
> >>>
> >>> The array is a two disk raid1 and hosts the root filesystem.
> >>>
> >>> Is it not possible/allowed to add a bitmap to an active/mounted array?
> >>
> >> It is. But it is busted.
> >>
> >> Either use an older mdadm (3.2.2 or earlier), or apply this patch
> >>
> >> http://neil.brown.name/git?p=md;a=commitdiff;h=4474ca42e2577563a919fd3ed782e2ec55bf11a2
> >>
> >> which has been sent to Linus already and should appear in -stable
> > kernels in
> >> a couple of weeks.
> >>
> >> NeilBrown
> >
> > Thank you for the explanation.
> >
> > --Larkin
> >
> > --
> > To unsubscribe from this list: send the line "unsubscribe linux-raid" in
> > the body of a message to majordomo@vger.kernel.org
> > More majordomo info at http://vger.kernel.org/majordomo-info.html
>
>
>
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next prev parent reply other threads:[~2012-03-21 20:03 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-03-19 16:44 Kernel oops adding bitmap Larkin Lowrey
2012-03-19 21:32 ` NeilBrown
2012-03-19 21:40 ` Larkin Lowrey
2012-03-21 13:21 ` CoolCold
2012-03-21 13:52 ` John Robinson
2012-03-21 20:03 ` NeilBrown [this message]
2012-03-22 19:54 ` CoolCold
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