Installation with Raid, etc... [dead issue, don't bother reading]

Question

I'm trying to install arch using RAID and LVM, following the wiki procedure in Installing with Software Raid or LVM.
I am able to get to the point where I install the kernel.  When I install it, the bottom of the screen flashes the "wrong fs type, etc" error, then the installer acts as though it is installing it anyway, going through the installation, configuration, and fallback configuration stuff.
If I continue, when I get to grub installation, I get the error that the drive doesn't exist.  I've found some forum threads on this which indicate (I think) that I need to run makedevs before going to grub installation.  If I type, makedevs, I get a command not found error.
The filesystem seems to be up and working, so I'm not sure what next steps I take to troubleshoot this.
bump:
So I tried the quickinstaller for some better control, which seems to help.  I also found this in the forums, it allows me to run makedevs.  /dev/md0 is already mounted at /mnt are my root, so I skipped the first line, not sure what else I could do there.
mount /dev/hdxY /mnt
chroot /mnt /bin/bash
mount -t sysfs none /sys
mount -t proc none /proc
makedevs
mount -a
Then vi /boot/grub/menu.lst :
kernel /vmlinuz26 root=/dev/md2 ro md=2,/dev/hda3,/dev/hdb3
Then launched grub as quoted in the wiki
Now, it doesn't say to exit the chroot to go on to grub - but it must be required because there is no /mnt/dev unless you do.  Once out, if I use
mount -o /dev /mnt/dev, I get a new error:
mount: can't find /mnt/dev in /etc/fstab or /etc/mtab
Which it isn't, but /mnt/dev does certainly exist.
I'm working on the very edge of my linux knowledge here, and suspect I'm making a fundamental error, but (obviously) don't know what it is.:(
bump:
Found this in discussion about the current iso, no access to the computer today but this will be my next approach.   
ok bug indetified:
i really apologize for this because it's something that shouldn't happen at all, but im only a human too.
/dev is not correctly mounted in installation system (during archboot cleanup i thought this is not needed sad )
--> setup cannot bind /dev to installed system.
--> autodetection of filesystem will fail, which will cause the default initrd to fail on boot.
2 workarounds:
First workaround before entering setup:
mount -t ramfs none /dev
/etc/start_udev
now setup works as it should!
Second workaround:
while using setup:
edit /etc/mkinitcpio to not include autodetect in HOOKS= array
1 workaround if you already installed and system doesn't boot:
use the kernel26-fallback.img as initrd in your bootloader
after successfull boot just fix the ramdisk:
mkinitcpio -p kernel26
bump:
I backed out and started all over a couple times, finally installed via Duke with updates.  Found that I had to reinstall filesystems to my hard drive; something obviously got messed up, and ultimately found a couple of "typos" that had managed to mess me up.  Because I fixed so many things on the way to installation, I can't tell you exactly what I did, so I'm marking this thread as a dead issue so people don't bother reading it.
Last edited by timm (2007-10-05 02:25:54)

Answer 1

I've been using LSR (Linux Software RAID) with Arch for a while now and it's never given me any trouble: I don't even know how that works since all I have to do is make sure the md module and the appropriate module for your RAID-type (in my case raid0.ko) is loaded: when these are compiled into the kernel, the md-module automagically finds my RAID-partitions and starts the correct md-devices in /dev.
I don't have any md-daemon running (I didn't even know there was one until I read your post).
And still everything just works.
What I think you need to do is repartition both of your RAID-1 discs and make sure your partition's type is "Linux raid autodetect" (type fd). Once you've done that, create the md-device and put a filesystem on it. Edit /etc/rc.conf and put "md" and "raid1" in the list of modules to be loaded at boottime, get rid of the mdadm service since it doesn't exist anyway.
Now after rebooting, once the RAID-modules are loaded they should detect and start up your RAID-array automagically. Check this with dmesg.