On Fri, 11 Oct 2013, Guillaume Betous wrote:

As I read that algorithm on the RAID 6 are way more complex, and rebuild 
time is longer, as I have only a Atom D510 as CPU, I consider that RAID 
5 is a better option.

It's an old myth that RAID6 uses a lot of CPU. It doesn't, not even 
considering you have an Atom D510.

But if you can explain that RAID 6 have pros I haven't seen, I'll
surely swith to RAID 6 (always want to learn :) ).

RAID6 will help you with drive failure plus random read error. RAID5 
doesn't do that.

My recommendation to you is to convert your RAID5+spare to RAID6.

-- 
Mikael Abrahamsson    email: swmike@swm.pp.se