[CentOS] Netapp like snapshots using Centos 5/6 direct attached storage

Hello,

I'm researching the best method of providing about 20 users in a production environment the same functionality as they would have on a Netapp NFS share.
The O/S I will be using is CentOS 5 or 6 (max flex on which one) and the hardware is a disk array directly (12 SAS disks 7TB un-configured brand new) attached to a HP 580 G 7.

I've done some reading on ZFS on Linux ,fuse-ZFS, BRTFS ,rsnapshot, snapFS. 

Any one have some advice or experiences to share?
  
Thanks,
spuds