Hallo, Proskurin,

Du meintest am 20.06.11:

I`m new to btrfs and do some testing now.

What we have:
SL6 - kernel 2.6.32-131.2.1.el6.x86_64
mdadm RAID5 with 8 HDD - 27T partition.

You should take a newer kernel. On my system I needed 2.6.38.5 and newer  
for btrfs; older kernels lead to unreadable partitions.

Viele Gruesse!
Helmut