With the imminent release of Debian Sarge, comes a new installer program, which is much more flexible than that of previous releases. Among many of the new features is support for installation with LVM, installation over an ssh console and even the ability to install over an infra-red link. However with these extra features comes an added layer of complexity, and for the new user, accessing the less commonly used features is not always straightforward.
This article intends to provide a step-by-step guide to installing Debian Sarge with a mirrored-disk configuration. This process can easily be extended to cover any RAID configuration that Debian Linux supports (concatenated disks, RAID5, etc).
Firstly, you'll need a system with two hard disk drives, and a CDROM drive. It is nicer if the drives are identical, but this isn't essential. The two disk drives should be on separate buses, if using IDE, otherwise the performance will be terrible. The system that I used for this article was a QEMU virtual machine. My hard disks were set to be /dev/hda and /dev/hdd, because QEMU insists that the CDROM must be /dev/hdc.
Once you have operational hardware, boot up the machine, and insert the Debian Sarge Linux installation disk into the CDROM drive. You should see the Debian swirl logo appear and a prompt that says "Press F1 for Help, or ENTER to boot:".
Debian Sarge's default kernel is 2.4.x, which would work fine for the task at hand. I have chosen to use 2.6.x instead, because I needed it for other reasons. We are also going to use 'Expert' mode to install the system, so that we get a wide range of options to choose from. So, to do this, we type 'expert26' and press Enter. Should we have wanted to use kernel 2.4 in Expert installation mode, we only would have needed to enter 'expert'.
Linux will now boot, and then start the installation program, which will present a menu of options, which is quite straightforward. Follow through the initial options "Choose Language", "Choose country or region", "Select a keyboard layout", "Detect and mount CD-ROM".
The next step is to load various installer components from the CDROM. The default Debian installer program only has the ability to install to the most common types of systems. To do anything more complex than this, we must load in modules for the additional functionality.
Select "Load installer components from CD"
Now we will be presented with a list of the optional components that we can choose from. We want to install our system with software RAID, so we should choose the "mdcfg" component. Scroll down to this option and select it by pressing space. Then select "Continue".