Just watched this and wanted clarification - I always though that if you had a selection of say, 4 x 320GB drives in a RAIDZ2, replaced one with a 500GB and then thought you might as well replace the others with 500GB, once all of them had been changed to the larger capacity, you would be able to utilize all of the 500GB capacity?
So to put it another way, you start a pool with 4 x 320GB
You then replace all drives with 500GB capacity drives
Only once you had replaced all of them, would you gain the extra space.
Is that wrong as I would be keen to know - not because I’m planning for that situation, but it might generally be helpful to know.