Re: LVM & RAID10

[Bean <bean123ch@gmail.com>]

On Tue, Nov 25, 2008 at 9:08 AM, Wojciech Pyczak <nissarin@gmail.com> wrote:
> Hello!
>
> I have some troubles setting up grub2 on my configuration. After I bought a
> new computer I decided to "go wild" and setup everything on top of LVM, with
> LVM itself on RAID array. I expected there will be some problems and here I
> am :)
>
> Few words about configuration - I have 2x WD 640GB HDDs, there is single
> partition on each drive, those partitions are used to build RAID10 array.
> Aray itself consists of 3 drives (third one is "missing" since I use it in
> my "old" computer), like I mentioned before it's level 10, with 256kB chunks
> and far2 layuout. On top of that there is LVM2, consisting of single
> "storage" group (32MB extents), divided into few logical volumes, including
> volumes named "root" (/) and "boot" (/boot).
>
> I used latest RescueCD to made this up and installed fresh gentoo. I managed
> to build entire system, I only needed to boot it. So, I emerged (using my
> own custom ebuild) Grub2 SVN version (successfully) and tried to make
> everythig work but it appers life is not so easy :P. The only clue I have is
> (completly mysterius to me) error message: "We don't support multiple
> metadata areas".

Hi,

This error come from lvm, perhaps you can try raid10 first.

>
> AFAIK both LVM and RAID10 are supported and it's possible to boot grub from
> LVM volume, am I wrong ?
> Or perhaps I'm missing something ?
> Is there any example of LVM/RAID config files ?
> What happens if array (RAID 5, 6, 10) is incomplete (disk failure/missing) -
> maybe that's the problem ? And in that case, how I'm supposed to boot system
> in such situations ?

Yes, it should work out of the box, although there is a small catch.
If you're using raid5/raid6 and one/two of the disk is missing or
corrupted, you need to add module raid5rec/raid6rec using the --module
option in grub-install.

-- 
Bean