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

Thu Jan 26 07:39:04 UTC 2017
Pete Biggs <pete at biggs.org.uk>

> If you are using RAID 1 kernel mirroring, you can do that with /boot too,
> and Grub finds the kernel just fine. I've done it many times:
Hmm, OK. I wonder why anaconda doesn't do it then.

Reading various websites, it looks like grub2 can do it, but you have
to make sure that various grub modules are installed first - i.e. do
something like 

  grub-install --modules='biosdisk ext2 msdos raid mdraid' /dev/xxx

I don't know if they are added by default these days.

The other gotcha is, of course, that the boot sectors aren't RAID'd -
so if /dev/sda goes, replacing it will make the system unbootable since
it doesn't contain the boot sectors. Hot swap will keep the system
running but you have to remember to re-install the correct boot sector
before reboot. If you have to bring the machine down to change the
disk, then things could get interesting!