ZFS or UFS for 4TB hardware RAID6?

[Maxim Khitrov]

Hello all,

I'm about to build a new file server using 3ware 9690SA-8E controller
and 4x Western Digital RE4-GP 2TB drives in RAID6. It is likely to
grow in the future up to 10TB. I may use FreeBSD 8 on this one, since
the release will likely be made by the time this server goes into
production. The question is a simple one - I have no experience with
ZFS and so wanted to ask for recommendations of that versus UFS2. How
stable is the implementation and does it offer any benefits in my
setup (described below)?

All of the RAID6 space will only be used for file storage, accessible
by network using NFS and SMB. It may be split into separate
partitions, but most likely the entire array will be one giant storage
area that is expanded every time another hard drive is added. The OS
and all installed apps will be on a separate software RAID1 array.

Given that security is more important than performance, what would be
your recommended setup and why?

- Max