From mboxrd@z Thu Jan 1 00:00:00 1970 From: Neil Brown Subject: Re: Moved drives between machines... now, MIA. Date: Mon, 8 Feb 2010 16:55:02 +1100 Message-ID: <20100208165502.13e53fd8@notabene.brown> References: <290032.65343.qm@web51308.mail.re2.yahoo.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: <290032.65343.qm@web51308.mail.re2.yahoo.com> Sender: linux-raid-owner@vger.kernel.org To: Jon@eHardcastle.com Cc: jd_hardcastle@yahoo.com, Ryan Wagoner , Ken D'Ambrosio , linux-raid@vger.kernel.org List-Id: linux-raid.ids On Tue, 2 Feb 2010 08:35:23 -0800 (PST) Jon Hardcastle wrote: > --- On Tue, 2/2/10, Ken D'Ambrosio wrote: >=20 > > From: Ken D'Ambrosio > > Subject: Re: Moved drives between machines... now, MIA. > > To: "Ryan Wagoner" > > Cc: linux-raid@vger.kernel.org > > Date: Tuesday, 2 February, 2010, 15:36 > > > You did make a new mdadm.conf > > with the correct devices for each array > > > right? If not try running and seeing if your arrays > > come up. If they do > > > then copy /tmp/mdadm.conf to /etc/mdadm/mdadm.conf > > > > > > mdadm --examine --scan --config=3Dpartitions > > > /tmp/mdadm.conf mdadm > > > --assemble --scan --config=3D/tmp/mdadm.conf > >=20 > > Hmmm.=C2=A0 I was hoping what I'd been doing had been > > "wrong" somehow, but what > > you've got is pretty much what I did.=C2=A0 And here's the > > output (which > > confuses the living Hell out of me): > >=20 > > ARRAY /dev/md0 level=3Draid1 num-devices=3D2 > > UUID=3Df2de81aa:ccd40fc9:01dc0b99:e8df86c1 > > ARRAY /dev/md1 level=3Draid1 num-devices=3D2 > > UUID=3D837925b3:f9f0e1b1:02f450c9:474613c9 > > ARRAY /dev/md1 level=3Draid1 num-devices=3D2 > > UUID=3Db6af942c:119cd1fc:02f450c9:474613c9 > >=20 > > (Note how the second half of the last two UUIDs is the > > same, and the last > > two UUIDs are both for /dev/md1.) > >=20 > > Guess it's time to go to the tapes, huh? > >=20 > > Thanks, > >=20 > > -Ken > >=20 > >=20 >=20 > So basically all you have done is remove the drives from 1 machine an= d insert in another? I would really hope that, that would not trash dat= a... I have never tried it mind. i did recently change my drive order t= hough just unplugged and re-plugged in a completely new order. >=20 No, that in itself would not cause a problem. If you have two machines each with /dev/md1, and you move the devices f= rom one to the other, that other will appear to have two different /dev/md= 1 which would be confusing. mdadm tries to be careful and will only asse= mble one of them, or will assemble them both with different names. The commonality in the tail of the uuid of the two /dev/md1 array is si= mply because they were created with the same HOMEHOST. You can assemble the arrays manually with something like mdadm -As /dev/md1 --uuid=3D....... mdadm -As /dev/md1a --uuid=3D...there-other-one.... Then look at the contents. NeilBrown -- To unsubscribe from this list: send the line "unsubscribe linux-raid" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html