Root RAID HOWTO cookbook

15. Appendix H. Setting up ROOT RAID on RedHat

From the linux-raid at vger.rutgers.edu mail list.

!    Has anyone figured out how to do root-mounted RAID (as per
!    the Root-RAID HOWTO) using RedHat? The problem is that there
!    is no equivalent of Slackware's setup to install the root
!    filesystem to the RAID device. All RedHat installs have to
!    run from the install floppy, which makes it almost
!    impossible to get at the md devices and utilities during the
!    install.
! 
!    I think it's much easier to go out of the distribution and do it by
!    hand!!

Assuming you have enough RAM (or a spare hard disk), install a minimal
system onto what will be your swap space (or onto your spare hard disk)
and/or /boot.  Now do your mkraid, your mke2fs, mdrun, and mount.  Next, do:

        tar clf - / | tar xpfC - /mnt/raidwasmountedhere

(you may want a "v" in the second tar's flags)
Once this is done, you can set up lilo (or whatever) so that the new
raid partition is root.  Then go in with RPM and/or glint (I hate
glint's behavior in the face of failed dependencies, which was fixed
but they broke it again for RH5.0 plus you can go back and forth
forever between an old and a new version of a package without
realizing the other version is installed) and install what you
really wanted.

All this assuming you couldn't sneak in at some point in the install
and do your mkraid then at the VC with the shell prompt...

!    I'm building a server at the moment and I think it would be tidier
!    and less likely to cause problems in the future if I start with
!    glibc2, rather than move to it later.
!
!    Me too.
!
!    The reason I'd like to be able to use RedHat is that they
!    are the only major distribution that I know of with a
!    glibc2-based release. 
! 
!    Debian works fine with me. There isn't a CD yet, but you can grab the
!    distribution by ftp.

I avoided root-raid like the plague, largely because initrd is an
extra, very fragile step (having to rdev, and having lilo depend on
the bios' ID number to find the kernel's partition, are bad enough!).
However, Red Hat does have a nice mkinitrd script, needed since they
left all their SCSI drivers modular.  Hack that to include your
raid utils, make sure your mdadd -ar is in the right spot in
/etc/rc.d/rc.sysinit (before any fscking) and make sure mdstop -a is
in /etc/rc.d/init.d/halt after the RO-remount of /, and go for it!

Keith kwrohrer at enteract.com