Remounting geli and ZFS partitions

As I did a clean install and not an upgrade of my FreeBSD 8.2 to 9.0, I have to reconfigure everything from scratch :-)

I have 4 Western Digital disks with data - all in RAID-Z. And because they are Western Digital, they have 4K sectors and don't work well with ZFS. So I also have encrypted them with geli - a standard [trick](http://www.cod3r.com/2010/06/zfs-on-western-digital-ears-drives/.

I had a huge problem attaching the geli devices after reinstall.

The devices have changed names, and the geli attach will fail if using the "alias" device :-/

So if using e.g. ad6s1e as provider under 8.2, then attach will fail under 9.0 with:

1geli: Provider ad6s1e is invalid

The /dev/ad6s1e is now an alias for /dev/ada0s1e (look in the dmesg).

So remember to keep this in mind when editing rc.conf and loader.conf. Also remember to copy the zpool.cache in /boot/zfs in order for the zfs mounts to work.