Re: [gentoo-amd64] How to install to a RAID set?

[Boyd Stephen Smith Jr.]

On Wednesday 17 May 2006 05:47, Peter Humphrey <prh@××××××××××.uk> wrote 
about 'Re: [gentoo-amd64] How to install to a RAID set?':
> Well, I tried the Software-RAID-HOWTO, and used a SuSE 9.3 DVD I had
> lying around to create /dev/md0 to /dev/md5 on the /dev/sd[ab] disks
> that are attached to the SATA interface. SuSE installed just fine and is
> happy to run on these devices.

Ah, very good, you are using pure software raid.  Did you use raidtools or 
mdadm to create these devices?

> In spite of that, when I boot the Gentoo 2006.0 installation CD and tell
> it:
>
>    gentoo dodmraid dmraid=-ay

You don't need either of those options.  dmraid is "firmware" raid, nor 
pure software raid.

> It says in the boot sequence:
>
>    Activating Device-Mapper RAID(s)
>    No RAID disks

Sounds normal, since you didn't say you created any dmraid devices.

> Then when the image has booted, I say  fdisk -l and I see the partitions
> on /dev/sda and /dev/sdb with no trace of /dev/mdX.
>
> What am I doing wrong?

Probably nothing.  If you used the (old, busted) raidtools way of creating 
the md devices, there's no metadata on the devices themselves that tells 
Gentoo the devices are part of a raidset.  So, there's no way for Gentoo 
to create the /dev/mdX devices automatically.  You should be able to grab 
your raidtab from your SuSE initrd/initramfs or / partition and activate 
the devices your self though.

If you used the (new, hotness) mdadm way of creating the devices, well, 
Gentoo probably /should/ have automatically created the devices.  You 
might want to file a bug.  In the meantime, the booted image should 
contain mdadm and you should be able to use the "scan" and "assemble" (?) 
options to create your devices.

-- 
"If there's one thing we've established over the years,
it's that the vast majority of our users don't have the slightest
clue what's best for them in terms of package stability."
-- Gentoo Developer Ciaran McCreesh