Convert RAID1 to RAID5

[crazyeddie]

I run a RAID 1 with two 500GB-HDDs in my Thecus.
Now I want to upgrade it to 4x500GB with RAID5.

Is it possible to create that RAID without loosing my data?
Or must I clean all drives before creating?

CrazyEddie

[crazyeddie]

Okay, I got it.
No chance to keep my data.
I had to delete the raid1 and build a new raid5.