[CentOS] CentOS 7 install on one RAID 1 [not-so-SOLVED]

[Valeri Galtsev]

On Tue, January 24, 2017 4:14 pm, m.roth at 5-cent.us wrote:
> So, it installed happily.
>
> Then wouldn't boot. No problem, I'll bring it up with pxe, then chroot and
> grub2-install.
>
> Um, nope. I edited the device map from hd0 and hd1 being the RAID to
> /dev/sda and /dev/sdb, then ran grup2-install. It now tells me can't
> identify the filesystem on hd0, and can't perform a safety check, and
> gives up.

This is an interesting logical contradiction (unless things progressed
much farther than what I last read):

If you want to boot off your RAID1 device you need software RAID piece of
code already running, i.e. kernel already loaded, to load which which in
the first place you needed md0 or whichever device to exist to load it
from...

The only way around that I remember people were using was: cutting small
partition off the drive to keep it as a regular partition, and have /boot
on it. The rest of the drive can be different partition which can
participate in software RAID. For mirror (RAID-1) I remember people were
cutting the same piece off the beginning of both drives, one is always
active /boot (another can be maintained as a copy of it, but if you loose
first drive, you will need to install grub bootsector to second drive
pointing to /boot copy on that drive for loading initramdrive).

Anyway, good luck. Getting hardware RAID controller will be waaay less
hassle at all stages of your machine's life.

Valeri

>
> What am I missing? Google is not giving me any answers....
>
>       mark
>
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++++++++++++++++++++++++++++++++++++++++
Valeri Galtsev
Sr System Administrator
Department of Astronomy and Astrophysics
Kavli Institute for Cosmological Physics
University of Chicago
Phone: 773-702-4247
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