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Asked: 2012-07-26 06:17:20 +0800 CST

Advanced configuration of Grub2 for RAID5 + Encrypted LVM where /boot needs redundancy

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I recorded my complete installation until failure in case you have a question about the installation which I did not provide an explanation for below: http://www.youtube.com/watch?v=BVe5vja3keo

During partitioning I created a software RAID 5 volume spanning three identical disks. On that volume I created an encrypted volume, which I created an LVM inside containing two logical volumes inside a volume group. One logical volume for /boot and one for / (the rest): enter image description here

When it is time to install Grub to the MBR I get the error Executing grub-install /dev/sda failed. This is a fatal error: enter image description here

After that I completed the installation without installing a boot loader.

I would greatly appreciate it if someone could help me out!

  • I do want redundancy for /boot so placing it outside the RAID 5 volume is not an option.
  • I have tried placing a /boot partition immediately inside the RAID 5 volume and that doesn´t work automatically either.
  • If it is possible I´d like the /boot inside the LVM, but if it is not having it inside the RAID volume would be sufficient.
  • I know that a software RAID is sub optimal for performance and that a hardware one is preferred. However, my budget does not allow for one and redundancy and encryption are my primary concerns.
ubuntu

2 Answers

  1. If you absolutely have to do Software RAID, I'd suggest keeping /boot out of your encrypted/LVM partitions.

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  2. Create a separate RAID partition on each of your disks for /boot, then RAID1 it (RAID1, not RAID10).

    From my similar server:

    $ cat /proc/mdstat 
Personalities : [raid1] [raid6] [raid5] [raid4] 
md1 : active raid6 sdc2[3] sdd2[1] sdb2[0] sda2[2]
      143090816 blocks level 6, 64k chunk, algorithm 2 [4/4] [UUUU]

md0 : active raid1 sdc1[2] sda1[0] sdd1[3] sdb1[1]
      136448 blocks [4/4] [UUUU]

    And of course, don't forget about the MBR!

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