Raid 1 on btrfs

Hi everyone, I’m new to rockstor and to btrfs.
It might be a stupid question…

I have an 8tb drive and a 2tb… If I create a 2tb pool can I mirror it to the 2tb drive?

Then I can have important data raided,2tb and not important data not raided 4tb.

I don’t think Rockstor provides the capability to create multiple pools on a single disk. I’d be hesitant to do it manually as this sounds like something that might be GUI breaking.