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I would like my RAID10 to survive the failure of the bootdisk. I want to write grub to the MBR of each disk in the array so that in the case of a failure the array will still boot on the remaining members.

I have a 4 disk array, so in theory I only need 2 grub MBRs, but I don't see the harm in putting the bootloader on all 4.

Grub folder is: /boot/grub Root is: (md0)/

Step by step, how do I install grub on each drive?

Antonius Bloch
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  • I accomplished this under ubuntu natty using the automatic partitioning. Unfortunately I can't really write a decent answer because the install did all the heavy lifting. On a high level a small partition was created that grub uses to store data, and then grub was installed on the mbr of both disks. – Antonius Bloch May 27 '11 at 19:19

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I see you've already figured out how to accomplish this from a high level interface, but for the sake of anybody else who would like to learn how to configure software RAID10, I'll link to a fantastic article that goes into great depth on how to accomplish this. Rather than copy the article verbatim, I'll link to it instead. I used this article as a guide to set up RAID 10 for a file server; it also explains how to configure GRUB to successfully boot after a disk failure.

Diblo Dk
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Richard Keller
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    Still this is mostly a link only answer and as links become unavailable, it might loose its appeal after some time. Could you edit it to include the essential steps included in the article? – Konrad Gajewski Aug 02 '19 at 20:05
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I usually don`t do this with grub. The problem - which is not addressed in the referenced article is:

If you loose sda (=hd0) your previous sdb (=hd1) will become sda (=hd0) which confuses grub: It was installed to sdb/hd1.

I use dd from one partition to the other to copy the whole boot-partition (including grub-setup).

And don`t forget to set up your bios so it will continue to boot in case of a drive failure. ;-)

Nils
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    Provided you install and setup GRUB on both drives used for the RAID 0 configuration and also reference the lowest possible drive (hd0) in the config file, there won't be a problem, since even if hd0 fails, hd1 will take its place and become hd0. – Richard Keller May 31 '11 at 20:23
  • Is this grub legacy or grub2 you are talking about? – Antonius Bloch Jun 01 '11 at 13:01
  • My experience is with using GRUB legacy - I'm not sure whether there would be any difference using GRUB 2. – Richard Keller Jun 01 '11 at 13:47
  • I think modern Grub is getting past this problem using the partition UUID to identify the disk/partition regardless of device name changes. – Antonius Bloch Jun 04 '11 at 16:47
  • "modern" = grub2 ? That would be a real reason to switch to grub2. – Nils Jun 04 '11 at 20:58