[CentOS] Software RAID in CentOS (EL)

Is it just me, or does anyone see something seriously wrong with the
Software RAID example?

http://mirrors.cat.pdx.edu/centos/3/docs/html/rhel-sag-en-3/ch-software-raid
.html

Figure 12-4

Isn't RAID supposed to be redundant disks, not redundant partitions? If that
hda disk goes bad, the raid and redundancy is nowhere to be found along with
your data. Right?

Is there a way to make each disk a single software raid partition, then use
slices of that partition for your drive partitions with LVM or something? I
basically want to encapsulate the partitions for the operating system with
RAID so that if a disk drive fails, it can be repaired.

I have never used this function before, so set me straight if I'm just
missing the point.

Thanks,
Chuck