Hi, I have an old Dell server I want to repurpose as a storage server and I decided to use zfs. I have read that gradual increases are best done with mirrored vdevs and only if I want to max out, I can choose Z2. What are your experiences in practice?

I like to go the gradual increase route because I cannot afford to maximize from the beginning. I like to start with ~10TB usable space. The server has at least 8 free drive bays. Should I go with a mirror as my first vdev or go 6x3TB with Z2? Ideally I want to be able to add more vdevs to the same pool in the future.

I am also curious whether it is a bad idea to have an uneven pool with mixed vdev types, the first being mirror and the second Z2. Will the vdevs eventually even out over time because zfs is a CoW filesystem?