Re: Woody root on RAID and 2.4.17
You came up trumps. Your pointers got me running woody with root
on software RAID. Thanks!
STOP PRESS: I've now got woody with root fs on LVM on software RAID-1.
The ultimate server weapon... Watch this space.
I'd like to write all this up in an informal HOWTO which I'll put up on my
site. I would like to give you credit for your RAID-lilo pointers. Would
you like me to put up your email address in the credits or not? If you'd
like me to include any other details, please forward them.
I did it differently to how you suggest, in a way that leaves lilo.conf,
fstab, /boot and the MBR on the single disk we start from completely
untouched and may even be a bit easier to do. The key is editing the
lilo.conf copied to the RAID only, and doing
chroot [target] /sbin/lilo
to install an MBR to a disk other than the one with the initial
Starting with an initial install to a single disk, it goes a bit like
/dev/md[boot]: RAID-1 array for /boot fs
/dev/md[root]: RAID-[1|4|5] array for root fs
(I've only tried RAID-1 but I'm confident
RAID-4 and -5 will work too).
/dev/[h|s]d[raid-mbr]: Disk to whose MBR we will install lilo for
the RAID system; must not be the disk to which
we make the initial single-disk install.
- We install to a single disk. It makes things simpler if this disk
is partitioned the same way as the others will be. Set the BIOS to boot from
this disk and install.
- Obtain or compile a RAID kernel and reboot with it.
- Install raidtools-2.
- If you're going to be using 2.4.x with devfs, install devfsd.
- Write an /etc/raidtab with the partitions on the disk we've just
installed to marked as "failed-disk". Make sure these entries are not the
first ones in each array.
- Create the RAID arrays:
- Make filesystems on them:
- Mount the RAID array which will be used as the root fs under /mnt
mount /dev/md[root] /mnt
- Copy the root filesystem to it:
tar cplf - -C / . | tar xvpf - -C /mnt -
- Mount the other raid arrays under /mnt: /mnt/boot, /mnt/usr etc.
Instead of issuing all those "mount" commands, you might as well put these
mounts in /etc/fstab and do:
In that way, they get mounted automatically in case you need to
reboot into the single-disk system and work on them.
- Copy the other filesystems to the
tar cplf - -C / [boot|tmp|usr|other] | tar xvpf - -C /mnt
- Edit /mnt/etc/lilo.conf and include:
--- begin relevant lilo.conf excerpt ---
# The disk we will install the RAID MBR to.
# We should leave the MBR on the initial install
# disk alone until we've successfully booted from RAID,
# so choose another disk.
# We will use the BIOS to switch this disk to the
# first BIOS id when we want to boot from it.
# The RAID-1 array for the /boot filesystem
# Write the RAID MBR to the above disk only
# Root filesystem device
--- end relevant lilo.conf excerpt ---
- Install lilo to the disk we've chosen to hold the RAID MBR:
chroot /mnt /sbin/lilo
- Edit /mnt/etc/fstab to mount the RAID filesystems instead of the
- Reboot, go into setup and change the BIOS settings to boot from the disk
we've installed the RAID MBR to.
- Boot into the RAID system. If something goes wrong, use the BIOS
setup to get the system to boot the disk with the initial installation and
- Once booted into the raid system, edit lilo.conf and change it so the
MBR is installed to all disks in the array. More details later when I've
verified I can use the BIOS setup to boot from any one of the disks.
- Edit /etc/raidtab and change the "failed-disk" entries to "raid-disk".
Add the partitions on the disk with the single-disk installation to the
arrays with raidhotadd.
- Run lilo and reboot to check that you can now boot from any of the
- Celebrate appropriately.
Thanks again and best regards,
| George Karaolides 8, Costakis Pantelides St., |
| tel: +357 99 68 08 86 Strovolos, |
| email: firstname.lastname@example.org Nicosia CY 2057, |
| web: www.karaolides.com Republic of Cyprus |