On Thu, May 26, 2011 at 09:40:16AM -0700, Jiang, Dave wrote: > > -----Original Message----- > > From: linux-raid-owner@xxxxxxxxxxxxxxx [mailto:linux-raid- > > owner@xxxxxxxxxxxxxxx] On Behalf Of FDi > > Sent: Thursday, May 26, 2011 12:43 AM > > To: linux-raid@xxxxxxxxxxxxxxx > > 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. -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
