Re: Boot from LVM2 on RAID1 on 2xRAID5

[Richard Michael]

Mike,

> Why not use Raid-10 instead of this more complex setup?

I don't much about RAID10, and it's an mdadm special case.  I felt it
was cleaner to just have two separate arrays (well, three..).  Also, I
need to remove half the array on a regular basis, and rejoin it
afterware for resync.  I'm going to read about RAID10 and see if I can
do that.

>> Can grub2 boot such a nested configuration?  If so, what special
>> steps
>> must I take to install the bootloader?  (I'll install the system with
>> grub-legacy using Fedora or another distro, then migrate to grub2.)
>
> I played around with this myself a little bit. Currently Grub2 only
> understands the RAID superblock version 0.90.
> Since this only supports up to 2TB of RAIDs I actually have to
> partitions
> on every disk. The first one is part of a RAID-1
> with a 0.90 superblock. The other partition is part of a RAID-5 with a
> 1.0
> superblock.
> Nevertheless you really should think about setting up a RAID-10
> instead. (+
> a small /boot RAID-1 partition)

Yes, thanks for the tip.  I didn't know about 0.90 vs. 1.0 superblock
size limitation.  (It would be frustrating to discover when I want to go
past 2TB!)

It is planned for Grub2 to support booting from 1.0 superblocks?

Regards,
Richard