Upgrade capacity and disks without losing my setup?

[spikemixture]

You have said you have your data backed up "already have 2 4TB ones doing that job, "

Then who cares about how you setup /move your new drive

Start from scratch with a new fresh install

[Gryzor]

nothing like this neccessary ..just do as said before

- migrate to raid1
- expand via procedure by:
swapping the 2TB with a 4TB
swapping the 4TB in place (format it quickly so its new to the nas)

Ah now I'm getting somewhere!

-insert 4TB in bay 2: check
-migrate to RAID1: check
-swap the 2TB from bay 1 with a 4TB: check
-"swapping the 4TB in place" - do you mean in bay 1 or 2?

-even if I format it quickly, won't this leave me with just a RAID1 2TB set up?
-can the disks be reliably hot-swapped in such scenarios?

Thanks again!

@dolbyman: in my OP you'll see that stumbling block here is keping my OS setup, I really don't want to start from scratch...

[dolbyman]

with "in place" I mean the same bay you took it from

the nas just needs to go through the procedure to enable capacity expansion..

the format is done, so the disk seems "new" to the nas

[spikemixture]

I really don't want to start from scratch...

I totally understand. I spend days/weeks setting things up exactly how I want. I hate starting from scratch.
But !
But you know many/most times it takes longer fiddling around than starting from scratch!