Adding Software RAID under Linux

Note: The following instructions and examples are for taking 2 hard drives and creating 2 RAID-1 arrays. Please adjust your command accordingly.

Make sure that the Linux can see the disks
Install mdadm
```
yum install mdadm
```
Partition each disk into the required sizes. That is, if you plan to have the array create 2 arrays, you will need to partition EACH drive into two. Make sure the drive partitions are of equal size.
```
# fdisk /dev/sda
# fdisk /dev/sdb
```
Change the system type (a.k.a. system id) of each partition to be 0xFD (Linux RAID auto-detect). Make sure you write the changes to the partition table
```
# fdisk /dev/sda
# fdisk /dev/sdb
```

Create the arrays.

# mdadm --create /dev/md0 --level=1 --raid-devices=2 /dev/sda1 /dev/sdb1
# mdadm --create /dev/md1 --level=1 --raid-devices=2 /dev/sda2 /dev/sdb2

Adding_RAID