RAID5 With Compaq AlphaServer ES40

Dear all,

	I have one Compaq AlphaServer ES40 with 8 hard disks - 8GB each.
	If I loaded Raided Utility program from diskette ( RAID ARRAY 
230/PLUS   WS RX 23 2 RAID CONFIGURATION UTILITY V1.0B FOR ALPHA) and tried 
to choose automatic configuration. Then choosing RAID5. I would get the 
following message:
	"Automatic configuration FAILED, a all drives are not of the same size or 
the number of drives less then 3."
	If I chose JBOD. I could do it successfully.

	I want to use RAID5.
	How can I do?	

	Your help will be highly appreciated.
	Thanks

Regards,

	Lonh