Lenny (5.0) and later support having the root and /boot partition on RAID volume. Actually, you can have root on RAID1+LVM partition.

This page contains some screenshots to demonstrate it, and applies to Debian 5.0 through, at least, 8.0.

Root on software RAID+LVM

In this example, we use virtual machine (qemu or kvm)... we can play, and break them ;-)

Of course, you need to download a cdrom image.

Root on RAID+LVM example

Those few screenshots show how to install root on lvm on raid :

Once you have reach DebianInstaller partitioning screen...

Choose manual partitioning, then on each disk, manually create a partition (same size on both disks).

Create partitions for RAID

Configure RAID

Configure LVM

Use the LVM volumes

Install the bootloader (GRUB)

In Jessie (8.0), and I believe Wheezy (7.0), the installer will install GRUB even on RAID installs. However, GRUB can not install to a RAID device (e.g., /dev/md0), but will nonetheless work fine.

Install the bootloader (lilo)

At the end of the installation...

Reboot Debian

Using D-I rescue, to reinstall lilo

Thanks to DebianInstaller's rescue mode, it's very easy to recover a problem :

See also