Copying Data to NAS, reusing source HDD in NAS

[CWiz]

I have 2x 2TB HDD. One HDD is blank, the other has ~1TB of data on it i'd like to get onto the NAS.
Once the data is on the NAS, I'd like to use the HDD in the NAS for redundancy.

I've got the NAS assembled w/1 of the HDD installed. Do i have this process correct or is there an easier way?

1) build the NAS w/single HDD
2) upload the data from PC to NAS
3) Whipe/reformat HDD with original data
4) install reformated HDD into NAS, rebuild ZFS array

Is it possible to just build the NAS w/data already on one of the HDD w/o losing the data? Guessing it's a longshot

 

[Ericloewe]

You can make single-disk pool and expand the vdev to a mirror afterwards, but it's a somewhat hacky solution.