Software raid

After much reading and working to setup a raid array to install Arch linux:

I am trying to setup software raid 5 on an old system to be a web server.

I am using this as a guide to install/create the raid arrays:

I have 3 IDE drives

sda - 80G seagate
sdb - 80G seagate - both of theses are the same model
sdc - 160G wd - partitioned the same as the 80G

partition 1 - 256MB 32 cylinders - /boot raid 1
partition 2 - 256MB 32 cylinders - swap raid 0
partition 3 - 77G 2927 cylinders - / raid 5

the rest of sdc is not partitioned

I added another IDE controller card adaptec 1200A

The drives are installed

sda 1st controller master
sdb adaptec 1st controller master
sdc adaptec 2nd controller master

The adaptec does ATA 133 and the motherboard ATA 100.

All the drives pass badblocks and I zero'd the all drives with dd.

The raid array is created like this:
mdadm --create /dev/md0 --level=5 --raid-devices=3 /dev/sda3 /dev/sdb3 /dev/sdc3

After waiting for the drives to sync /dev/sda always fails, it doesn't give
an error just that it fails.

cat /proc/mdstat shows that sda3 has failed sdb3 is ok and sdc3 is ok
the other raid arrays are good/ok.

Switching drives around make no difference as the /dev/sda drive fails.

The other partitions are for boot (partition 1) raid 1 always works.
partition 2 swap raid0 always works.

I have tried to set this up on three different computers from a Pentium II
300 dell , AMD 800 slot A gigabyte mb and a AMD 2000+ asrock mb. These all
fail the raid 5 but the other raid 0 and 1 work.

Am I doing something wrong to setup the raid 5?

If I reboot after I create the raid arrays how do you restart the array(s)?

mdadm -a --force /dev/md0 doesn't work, it can't find the array in the conf
file, there isn't one at this time as I am working from Arch Linux
Install/Live CD to install to the raid 5 array.

I am going to replace the 160G drive with another 80G and resync the array
when I can find another 80G drive.


Can I still partition the rest of the 160G drive and use what is left as a
regular partition?