Comments on: Grub and root on partitionable RAID1 array http://bergs.biz/blog/2007/05/10/grub-and-root-on-partitionable-raid1-array/ Just another WordPress weblog Fri, 30 Jul 2010 11:33:34 +0000 http://wordpress.org/?v=2.5.1 By: Administrator http://bergs.biz/blog/2007/05/10/grub-and-root-on-partitionable-raid1-array/#comment-12085 Administrator Sun, 28 Dec 2008 08:33:52 +0000 http://bergs.biz/blog/2007/05/10/grub-and-root-on-partitionable-raid1-array/#comment-12085 @Julian Mehnle: That's exactly what I did: Create separate md devices for the no. of partitions I needed. @Julian Mehnle: That’s exactly what I did: Create separate md devices for the no. of partitions I needed.

]]> By: Julian Mehnle http://bergs.biz/blog/2007/05/10/grub-and-root-on-partitionable-raid1-array/#comment-12075 Julian Mehnle Sun, 28 Dec 2008 00:44:05 +0000 http://bergs.biz/blog/2007/05/10/grub-and-root-on-partitionable-raid1-array/#comment-12075 Grub 1 does not support booting from partitionable md devices, and neither does Grub 2! At the very least, as of today, the grub-probe and grub-install programs cannot yet handle /dev/md/d0 (AKA /dev/md_d0) style device names. There may be even deeper problems, but this alone has prevented me from setting up a system with partitionable md arrays today. Here's my Debian bug report in case you're interested: http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=509960 I then went back to creating multiple RAID component partitions and building multiple md devices from them. Grub 1 does not support booting from partitionable md devices, and neither does Grub 2! At the very least, as of today, the grub-probe and grub-install programs cannot yet handle /dev/md/d0 (AKA /dev/md_d0) style device names. There may be even deeper problems, but this alone has prevented me from setting up a system with partitionable md arrays today. Here’s my Debian bug report in case you’re interested: http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=509960

I then went back to creating multiple RAID component partitions and building multiple md devices from them.

]]> By: Administrator http://bergs.biz/blog/2007/05/10/grub-and-root-on-partitionable-raid1-array/#comment-7352 Administrator Mon, 01 Sep 2008 20:48:58 +0000 http://bergs.biz/blog/2007/05/10/grub-and-root-on-partitionable-raid1-array/#comment-7352 @Peter Cordes: Thinking about it again I in fact don't see any reason either why this shouldn't work -- <strong>provided</strong> that Grub can load the initrd. Are you sure that this is the case? @Peter Cordes: Thinking about it again I in fact don’t see any reason either why this shouldn’t work — provided that Grub can load the initrd.

Are you sure that this is the case?

]]> By: Peter Cordes http://bergs.biz/blog/2007/05/10/grub-and-root-on-partitionable-raid1-array/#comment-6672 Peter Cordes Thu, 07 Aug 2008 05:26:41 +0000 http://bergs.biz/blog/2007/05/10/grub-and-root-on-partitionable-raid1-array/#comment-6672 > Make sure the kernel has RAID-1 (and LVM if using it) built in. I don't see why that's a necessary step. There's no reason an initrd couldn't start a partitioned md device. Yeah, dpkg-reconfigure mdadm asks you what md devices the system needs to start, so just answer /dev/md_d0. Put root=/dev/md_d0p1 on your kernel command line. The major downside of this is that the whole drive has to be in RAID1. I usually RAID1 my /, /usr (or however I decided to partition on that machine), and /home, and RAID0 or lvm for the rest (which I usually call something like /data, and /var/tmp). > Make sure the kernel has RAID-1 (and LVM if using it) built in.

I don’t see why that’s a necessary step. There’s no reason an initrd couldn’t start a partitioned md device. Yeah, dpkg-reconfigure mdadm asks you what md devices the system needs to start, so just answer /dev/md_d0. Put root=/dev/md_d0p1 on your kernel command line.

The major downside of this is that the whole drive has to be in RAID1. I usually RAID1 my /, /usr (or however I decided to partition on that machine), and /home, and RAID0 or lvm for the rest (which I usually call something like /data, and /var/tmp).

]]> By: Administrator http://bergs.biz/blog/2007/05/10/grub-and-root-on-partitionable-raid1-array/#comment-3954 Administrator Thu, 31 Jan 2008 12:56:07 +0000 http://bergs.biz/blog/2007/05/10/grub-and-root-on-partitionable-raid1-array/#comment-3954 Please note the following comment in the howto you pointed me to: <blockquote>Make sure the kernel has RAID-1 (and LVM if using it) built in. You cannot use an initrd and modules. The kernel will only auto-mount raid arrays if the md module is built in.</blockquote> This is why it won't work under Debian -- at least not as long as you want to stick to "doing it the Debian way." Debian uses an initrd, and md is loaded as a module. Please note the following comment in the howto you pointed me to:

Make sure the kernel has RAID-1 (and LVM if using it) built in. You cannot use an initrd and modules. The kernel will only auto-mount raid arrays if the md module is built in.

This is why it won’t work under Debian — at least not as long as you want to stick to “doing it the Debian way.” Debian uses an initrd, and md is loaded as a module.

]]> By: Jarno http://bergs.biz/blog/2007/05/10/grub-and-root-on-partitionable-raid1-array/#comment-3951 Jarno Thu, 31 Jan 2008 09:38:32 +0000 http://bergs.biz/blog/2007/05/10/grub-and-root-on-partitionable-raid1-array/#comment-3951 how about this? http://somedec.com/downloads/howto-bootable-linux-raid1.html how about this?

http://somedec.com/downloads/howto-bootable-linux-raid1.html

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