This article describes how to setup a Linux system that can boot directly from a software RAID-1
device using GRUB. Even if one of the disks in the RAID array fails, the system can still boot. The
example uses Fedora Core 4.
System configuration
The test system is equipped with two 4GB IDE hard disks, one connected as master device on first
IDE channel (/dev/hda), the other connected as master device on second IDE channel (/dev/hdc). A
DVD-ROM reader is connected as slave device to the first IDE channel (/dev/hdb).
The goal is to setup a RAID-1 device to mount as / and to boot from. Another RAID-1 device will be
used as swap, to have a fault tolerant page swapping.
RAID-1 device Mount point Bootable Software RAID devices
/dev/md0 / Yes /dev/hda1, /dev/hdc1
/dev/md1 swap No /dev/hda2, /dev/hdc2
A real scenario just needs to provide a RAID-1 /dev/md0 that can be of any size (provided it is
enough hold the linux installation) and composed of any software RAID-1 partitions (each partition
in the array should reside on a different physical disk, possibly connect to different IDE channels, to
achieve maximum fault tolerance).
More complex configurations could include others RAID-1 devices to mount as /home, /usr, etc.
Installing and partitioning
Start the installation as usual booting from Fedora 4 DVD

and proceed until the Disk Partitioning Setup page is reached, then select “Manually partition with
Disk Druid”
1
First use the partitioning utility to create the software RAID partitions. In the example both disks are
split into a 3498Mb and a 596Mb software RAID partitions:
Device Type Size Mbytes
/dev/hda1 software RAID 3498
/dev/hda2 software RAID 596
/dev/hdc1 software RAID 3498
/dev/hdc2 software RAID 596
If the disks are new, the partitioning utility will ask to create a new partition table. If the disks