From: FDi <fld@r00t3d.com>
To: "Jiang, Dave" <dave.jiang@intel.com>
Cc: "linux-raid@vger.kernel.org" <linux-raid@vger.kernel.org>
Subject: Re: creating degraded raid1 with imsm metadata
Date: Sat, 28 May 2011 20:13:54 +0300 [thread overview]
Message-ID: <20110528171354.GA9767@r00t3d.com> (raw)
In-Reply-To: <D010E79907AF0D4E90B603DE907837D50490856E0F@azsmsx504.amr.corp.intel.com>
On Thu, May 26, 2011 at 09:40:16AM -0700, Jiang, Dave wrote:
> > -----Original Message-----
> > From: linux-raid-owner@vger.kernel.org [mailto:linux-raid-
> > owner@vger.kernel.org] On Behalf Of FDi
> > Sent: Thursday, May 26, 2011 12:43 AM
> > To: linux-raid@vger.kernel.org
> > Subject: creating degraded raid1 with imsm metadata
> >
> > Hello *,
> >
> > Since Intel's Matrix Storage Manager option ROM doesn't support creating of
> > degraded arrays I was wondering if I could use mdadm to make one? I had a
> > very hard time finding documentation about how mdadm is supposed to
> > work with imsm.
> >
> > The plan is to make a 2x1TB raid1 with one device missing and then later add
> > the other disk in once all the data has been copied to the degraded array. So
> > a typical raid1 migration scenario, which Intel oddly enough doesn't seem to
> > support with their option ROM.
>
> Not sure if that's possible but have you looked at the Linux RAID wiki on IMSM information?
> https://raid.wiki.kernel.org/index.php/RAID_setup#External_Metadata
I wasn't able to figure out how to do what I wanted based on the wiki,
but after lots of googling I found the exact commands:
mdadm --create --force -v -e imsm --level=container -n 1 /dev/md/imsm
/dev/sdb
mdadm --create -v --level raid1 -n 2 /dev/md/myraid /dev/sdb missing
However I also learned that these commands have to be done on the target
machine while its running with RAID mode selected from BIOS. Otherwise
you will get this warning:
mdadm: imsm unable to enumerate platform support
array may not be compatible with hardware/firmware
Continue creating array?
And indeed if that warning is displayed during the create, Intel's
option rom won't see a working array on the device. I'm kinda curious
why is this exactly? What kind of information mdadm uses from the
controller running in RAID mode?
When I created my array on the target machine using the commands from
above it worked correctly and Intel option rom saw the array and was
able to boot from the MBR I installed on the array as a test. Haven't
tested rebuilding yet.
next prev parent reply other threads:[~2011-05-28 17:13 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-05-26 7:42 creating degraded raid1 with imsm metadata FDi
2011-05-26 16:40 ` Jiang, Dave
2011-05-28 17:13 ` FDi [this message]
2011-05-31 14:36 ` Jiang, Dave
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