Upgrading my pool from 5x4TB to 3x6TB : what is the best way to move datas?

Hi,

my pool is made of 5x4TB + 3x240GB SSD cache.

I have had a very good deal on 6TB RED drives, so I will move my data to 3x6TB, maybe 4x6TB.

My data are x2 or x3 duplicated on the current pool.

What would be the best, most secured approach to move data? If needed, all disks : 3SSD+ 4x5TB +4x6TB can be pluged at the same time on my SAS expander.

I guess the first thing would be use Scanner on all new HDDs.

Then can I simply "Add" to the pool one 6TB then "Remove" one 4TB? and so on?

Thanks