RAID-1 boot partition and FC2->FC4 upgrade

[Justin Zygmont]

On Thu, 14 Jul 2005, Jack Howarth wrote:

> Aleksandar,
>    I found your posting at...
>
> https://www.redhat.com/archives/fedora-list/2005-March/msg05935.html
>
> concerning the proper handling of a RAID-1 boot partition under grub.
> Could you clarify a few issues on this. I found that anaconda in FC4
> could find all of my md partitions on my FC2 installation and mounted
> them. I have md0 as /boot, md1 as /, md2 as /var and md3 as swap
> and md4 as /home. The associated disk partitions are sdb1/sda1 with md0,
> sdb2/sda2 with md1, sdb3/sda3 with md2, sdb5/sda5 with md3 and
> and sdb6/sda6 with md4, Unfortunately anaconda in FC4 can't find the
> boot loader to update. From your posting I suspect this may because I
> have a grub.conf with...
>
> default=0
> timeout=10
> splashimage=(hd0,0)/grub/splash.xpm.gz
> title Fedora Core (2.6.10-1.771_FC2smp)
>        root (hd0,0)
>        kernel /vmlinuz-2.6.10-1.771_FC2smp ro root=/dev/md1 rhgb quiet
>        initrd /initrd-2.6.10-1.771_FC2smp.img
>
> ..etc. I recall installing grub on each hd0 and hd1 partition manually
> but could never get both of the drives to boot. Is it correct to assume
> that the problem is the root line in the grub entries? From your
> article it seemed that I should be deleting the lines with...
>
>        root (hd0,0)

it shouldn't because then you disable one drive the other one becomes 
hd0,0  I know from my past experiences that you will have to install grub 
manually to have each drive boot, so it should work since you did that.

> from grub.conf so that the boot partition is autodetected and then
> recreate both mbrs with...
>
> grub
> install --stage2=/boot/grub/stage2 (hd0,0)/grub/stage1 (hd0) \
>      (hd0,0)/grub/stage2 p (hd0,0)/grub/grub.conf
> install --stage2=/boot/grub/stage2 (hd1,0)/grub/stage1 (hd1) \
>      (hd1,0)/grub/stage2 p (hd1,0)/grub/grub.conf
>
> ...to allow each drive to boot if the other fails. I have a
> a sfdisk output of...
>
> # partition table of /dev/sda
> ...to allow each drive to boot if the other fails. I have a
> a sfdisk output of...
>
> # partition table of /dev/sda
> unit: sectors
>
> /dev/sda1 : start=       63, size=   208782, Id=fd, bootable
> /dev/sda2 : start=   208845, size= 61432560, Id=fd
> /dev/sda3 : start= 61641405, size=  6136830, Id=fd
> /dev/sda4 : start= 67778235, size=166658310, Id= f
> /dev/sda5 : start= 67778298, size=  4096512, Id=fd
> /dev/sda6 : start= 71874873, size=162561672, Id=fd
>
> ...though. This confuses me with regard to your description
> of the (hd0,0) being the partition number. I have been
> booting with 'root (hd0,0)' in grub.conf despite the boot
> partition being on sda1/sdb1. Is the 0 partition the MBR
> and not listed by sfdisk? I just wanted to be clear that
> I should use 0 for the partition in the grub commands above.
> Thanks in advance for any clarifications. I am hoping that
> if I make the above changes that anaconda will start recognizing
> the boot partition to update during the installation. Or is
> that yet another problem to solve beyond making grub.conf
> disk independent?
>                     Jack
>
>