Captains Log

There are two issues I stumbled upon while using/setting up a ZFS pool on FreeBSD:

1. Don't use generic device names, e.g. ad0, da1
   On Solaris it's quite common to specify a device without any slice, thus specifying the entire disk. While this works on FreeBSD, too, it leads to some nasty error messages during boot because any GEOM/GPT disklabel is removed. Create a GPT disklabel and add a partition using the freebsd-zfs style instead - or simply use a standard FreeBSD slice covering the entire disk.
2. Set geli_$dev_autodetach="NO" in /etc/rc.conf for all geli encrypted disks that will be part of your Z Pool
   This might be common knowledge, but I needed some time to figure this out: After a fresh boot issuing a "zpool status" obviously closed all geli providers, thus rendering the pool unusable. Well, this probably doesn't happen if you have zfs_enable="YES" in your /etc/rc.conf

 
PS: I installed FreeBSD-CURRENT 8.0, it comes with ZPool Version 13!