[ubuntu] Installing a new 2nd SATA drive then later another disk to RAID 1.

I am a complete beginning to Ubuntu. I want to move 2 3Tb Raid 1 discs in ZFS format to Ubuntu server 12.04. I understand that Ubuntu cannot access the ZFS, hence I will split the Raid getting one disk working on Ubuntu and setup the Raid on Ubuntu.

I have installed Ubuntu server 12.04 on to a 80Gb Sata disk. This I am going to use as the "system" disk and boot disk.
I have then fitted a 3Tb GParted Sata disk
I have booted with Gpart and set the disk up using VLM2 only because if I use ext4 46Gb of the 3Tb disk is not used. Some 2% why?

Then thru a battle with google I have got the disk volume and drive named thru VLM and mounted and can copy data on to it. (Although I have only copied a few Gb of the 1.8Tb to copy). But I have no confidence in what I have done is correct and no idea of the next step ! I want place another identical 3Tb drive in and Raid 1 this.

I am willing to ditch all I have done so far. No data has been lost. I have 1 3Tb still in the other server (although now not RAID1).

Is this the best guide to follow for installing the drive https://help.ubuntu.com/community/In...gANewHardDrive, copy the data across, setup the 2nd drive (same instructions) and then RAID 1 (instructions?).

Any help I would appreciate it - thanks.