Hi,
> If you really want ZFS, I would highly recommend looking into
> FreeBSD (Postgresql works great on it) or if you want to stick with Linux,
> look into mdadm with LVM or some other filesystem solution.
If you want to use ZFS because of its features, take a look at btrfs.
It provides a lot of the stuff supported by ZFS with usually better
performance on linux - and since the last few kernel revisions it is
finally in a state where I would dare to use it in production.
If you need highest performance, don't use a copy-on-write filesystem
like ZFS or btrfs, stick to ext4 or XFS ;)
Regards, Clemens