ZFS Few Questions

[list, mailing]

Hello everyone I just had a few questions about ZFS.
I normally use Hardware RAID 5.

Question 1:

With the ZFS snapshots what is the lost in drive space?

Hard drives I have:
4 x 500 GB = 1.5T on RAID 5

I have see lots of videos like: http://www.youtube.com/watch?v=CN6iDzesEs0

Question 2:

FreeBSD 9.0 installable on ZFS root?

Question 3:

Anyone Recommend for MySQL server? (Performance)

Question 4:

fsck used with when Server just turns off? (Fast or slower filesystem check
when compared to UFS on HW RAID 5 )
Taking note of: "FreeBSD 9.0 adds support for lightweight journaling on top
of softupdates(SU+J), which greatly reduces and need for background fsck,
and uses NFS-style ACLs by default."

Thanks for all your input on setting up a new FAMP box.

-- 
Ben Adams
http://www.SpryMed.com/