/boot on RAID with fedora16

[Chris Adams]

Once upon a time, Alex <mysqlstudent at gmail.com> said:
> I really can't believe the default install with two disks is LVM with
> striped disks and no redundancy. It's such a process just to create a
> RAID system.

It would be nice if anaconda recognized a pair of same-sized disks and
had an easy "click here for redundancy" button, rather than making users
go through all the steps manually, but that is not necessarily easy to
do (if I knew python half as well as I know perl, I might give it a
try).

> >> Yup, all three of my F16 servers have /boot on RAID1.
> >
> > I went through a PITA today getting F16 installed with /boot on a
> > pre-existing RAID1 partitions.
> 
> So you mean an upgrade? Or did you format the partitions? And if so,
> why not just reinstall?

It was a clean install to a new LV for / and a previously-empty
partition (extended) for /boot.  There was another LV/partition combo
for my previous Fedora system (F14).  I have a pair of 500G disks
(RAID1), and I never use that much space (most of my files are on my NFS
server), so I just carve it up for multiple OS installs (I also
sometimes will have a Rawhide install for testing).

> > I also discovered that the new-and-improved(not!) GRUB2 won't install to
> > partitions.  I use to set up multiple installs by:
> >
> > - create a small partition, install GRUB on it, and having its config do
> >  nothing but chain-load other partitions (this GRUB gets installed in
> >  MBR)
> > - set up each install with a separate /boot on an extended partition and
> >  install its GRUB to the partition rather than the MBR
> 
> Did you do this all with the installer? Or manually on the
> command-line from a shell within the installer?

I set up the top-level GRUB manually.  The installer lets you choose to
install the boot loader on the /boot partition instead of the MBR,
although it apparently no longer works (at least with RAID).

> > I couldn't get GRUB2 for F16 installed to my F16 /boot partition; it
> > would only install to the MBR.  I guess that's progress.
> 
> So then if I install to MBR, do I have to use a rescue disc to recover
> a system with a failed /dev/sda?

You need to install to both MBRs of RAID1 drives manually (anaconda
doesn't handle that).

It looks like switching back to motherboard "fake RAID" is going to be
the more reliable solution to configure (but not to operate; no update
bitmaps, no periodic verification, etc.).
-- 
Chris Adams <cmadams at hiwaay.net>
Systems and Network Administrator - HiWAAY Internet Services
I don't speak for anybody but myself - that's enough trouble.