1. First step is to put in all the drives and then boot up.
   Hopefully you know the device name, if not you may have to
   dig through /var/log/messages or dmesg command.

2. Once you know the device names of the drives (ex. /dev/sda /dev/sdb ..)
   Run (as root) fdisk on each one like:
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zorro:~# fdisk /dev/sda

The number of cylinders for this disk is set to 60801.
There is nothing wrong with that, but this is larger than 1024,
and could in certain setups cause problems with:
1) software that runs at boot time (e.g., old versions of LILO)
2) booting and partitioning software from other OSs
   (e.g., DOS FDISK, OS/2 FDISK)

Command (m for help):
---

Type 'n' and hit enter : this creates a new partition
---
Command (m for help): n
Command action
   e   extended
   p   primary partition (1-4)
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Type 'p' then '1'  then enter twice.
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p
Partition number (1-4): 1
First cylinder (1-XXX, default 1):<RETURN>
Using default value 1
Last cylinder or +size or +sizeM or +sizeK (1-XXX, default XXX): <RETURN>
---
Type 't' to change the filesystem type to Linux raid autodetect (type fd)
---

Command (m for help): t
Selected partition 1
Hex code (type L to list codes): fd
---
Type 'p' to check what you've done hopefully it should look something like this
---
Command (m for help): p

Disk /dev/sda: 500.1 GB, 500107862016 bytes
255 heads, 63 sectors/track, 60801 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

   Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *           1       60801   488384001   fd  Linux raid autodetect
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If you have done everything right type 'w' and enter, if you typed
something wrong just hit Ctrl-C and exit and start again.

Repeat this for each drive in the raid array.
---
Now the array is ready to assemble and format. You will need the package mdadm
on Fedora Core to do the following steps.
--

mdadm -C /dev/md0 -l 0 -n 3 /dev/sda1 /dev/sdb1 /dev/sdc1 

!!! this is not the exact command so here is what you need to know !!!
/dev/md0 is the device name, if there is already a raid device, you should
use /dev/md1 or /dev/md2 etc...
-l is the raid level, 0 is for RAID0 which stripes many drives into one.
-n is the number of devices to be added to the raid array at creation.
the /dev devices are the devices you are adding, so for this example I
am adding 3 devices /dev/sda1 /dev/sdb1 /dev/sdc1 to the array.
---

This should be all you need to do, the device should then be available as
/dev/md0 or what ever device name it is set to.

If the devices are all Linux raid autodetect, Linux should automatically
locate them on boot up.