[CentOS] fixing partition alignment ?

Thank you all for your feedback.
I was afraid that I had to move data around, well, I'll do then :)
It'll just be quite long and boring…

@Robert: Even if copying to another disk or box would be speedier, I'm
talking about moving twice ~90TB here, so…
@Les: I've had enough disk failures to be sure fault-tolerance
already works like a charm ^^
@Natxo: I'll do it keeping boxes up, disk per disk (fs lags a bit when
automatic replication kicks in due to 12/16/24/36 disks disappearing
from the pool like a single man :D)

Thanks again !