Terra Station with only 1 disk

[stargate]

Hello,

I have a TS-XEL/R5 terrastation with firmware 1.66. I had to reinstall all this and I have noticed that this is ONLY possible with 4 disks inside (from which it automatically creates a RAID0 array). It is possible to delete disk 3,4 out of the array (although it says array is degraded), not 2 however.

It is even possible to boot from 1 disk only. In this case LCD is red, device beeps sometimes. Isn't there a clean proper way where I can install the system on disk1 and use disk2-3-4 as I like in other raid/non-raid configurations?

Thanks