Arch Linux

Description: When attempting to install Arch Linux 2009.08 using the Wiki guide for Software RAID configuration. The installer fails to recognize the software RAID volume and is unable to boot. The generation of mkinitcpio.conf file appears to be overwritten during the install process and causes a config nightmare. The Wiki suggest the installer can read the mdadm.conf file however it appears to simply overwrite the file and then the newly booted Arch system is unable to boot.



Additional info:
* package version(s)
* config and/or log files etc.


Steps to reproduce: See below...

1 - Boot from 2009.08 i686 or x64 Core or Netinst disk.
2 - Select the 1st install option to boot into the live environment.
3 - Login as root / no password required.
4 - Create your partitions using the 'cfdisk' utility as shown below:

sda1 = 4096 MB (bootable) 83
sda2 = 200000 MB - type = fd

sdb1 = 4096 MB - type = 82
sdb2 = 200000 MB - type = fd

5 - Load the RAID1 modules with "#modprobe raid1" command.
6 - Create the RAID1 mirror with 'mdadm --create /dev/md0 --level=2 --raid-devices=2 /dev/sda2 /dev/sdb2'
7 - According to the Wiki run the following command: mdadm -D --scan >> /etc/mdadm.conf
8 - Run /arch/setup

From here its self explanatory. Setup network, configure your mount points, install packages, configure system (including the 'mdadm' hooks in 'mkinicpio.conf')

I don't even have my /dev/sda1 (/boot) partition as a part of the RAID so I don't have to deal with the whole Grub and RAID mess. I simply load MBR on /dev/sda (not /dev/sda1) and get a "Grub installed successfully" message. I can then reboot and watch my system fail to load /dev/md0. Because the installer over wrote my mdadm configs even though the Wiki seems to suggest it should self generate based on the steps. I could adjust the Wiki documentation which appears to try and do too much in one tutorial. You have LVM and RAID steps and even some stuff that applies to older versions of the Arch installer. It just seems like a mess of confusion. I think the real problem is the installer should handle the software RAID creation and integration into your newly create OS much smoother. It appears the transition from building your system from a live environment (which I love) to rebooting into your new system are flawed. Many people on the forums have found work arounds and other ways to get this to work but as someone who wants to see this done the right way...I hope someone can fix this in future releases. If you have any questions about my actions to replicate this problem, please let me know. I have done it some many times, it's a science by now.