I finally got a new array running, 3TB currently. One disk already had some data and there was an option to create a new array without losing that data. I figured that would safe me time (it didn't) so did it. Converting the whole crap took about 40 hours (not exaggerating) which was rather unexpected. Now I have a 3TB array which needs to be GPT, not MBR. Though converting to GPT can only be done on empty disks. Google so far doesn't come with some tool that can convert disks without losing data, would anyone know of a tool that can do such a thing? I don't feel like breaking the array, copying all data, converting the disk, copying everything back, restoring the array. It would take about 300 years to do that.