From mboxrd@z Thu Jan 1 00:00:00 1970 From: John Robinson Subject: Re: Install grub2 to /dev/md126 fails Date: Sat, 07 Jan 2012 15:39:06 +0000 Message-ID: <4F08671A.6090403@anonymous.org.uk> References: <123493149.466191.1325863934205.JavaMail.root@sz0019a.westchester.pa.mail.comcast.net> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <123493149.466191.1325863934205.JavaMail.root@sz0019a.westchester.pa.mail.comcast.net> Sender: linux-raid-owner@vger.kernel.org To: jlcenter@comcast.net Cc: linux-raid@vger.kernel.org List-Id: linux-raid.ids On 06/01/2012 15:32, jlcenter@comcast.net wrote: > Hi, > > I'm going to try again to build the raid1 array, but I was wondering > if the GPT partitions should be created first on the physical disks, > then create& assemble the array? Or, if the array should be > created& assembled, then partition the array? I'm raiding the whole > disk(s), not partitions. Reading the wiki, I get the impression the > first way is preferable, but most of the descriptions I've read > on-line suggest doing the latter. Also, for mdadm with GPT > partitions, is there any preferred order to the partitions, i.e., > does the bios boot partition have to be the first partition on the > array? If my understanding is correct, you want an IMSM array that can be booted by a uEFI BIOS? In which case, I think you need an array over the whole disks (which might give you a /dev/md127 for a container, and /dev/md126 for the data), GPT partition table over that, first partition a GPT boot partition (so you will be installing GRUB2 to /dev/md126p1 - this is NOT a filesystem partition), and then whatever you want after that, e.g. to keep it simple a /dev/md126p2 for swap and /dev/md126p3 for your filesystem. If you don't have a uEFI BIOS, it gets more complicated; you will need a hybrid MBR with a traditional boot sector and at least the GPT boot partition exposed :-( Caveat: I've read a lot but I haven't actually done this, so I may be talking rubbish... Cheers, John.