Did you go for lvm/ext4 install? If so:
pvcreate /dev/sdb1
vg…
lvresize …
resize2fs …
restart storage node with new space.
Or :
Create new identity…
Get new auth by email…
Sign tokens…
Open new port on router…
Start second docker process…
Wait 1 month for audit…
I think you should just add the second disk as more storage to your node BUT I also respect that there is a good and sensible argument for having a separate node for each disk.
At the mo I have both. I have a two disk node that I extended and another that is single larger disk.
Replacing your smaller disk with a larger one is good too. Next you can start a new node with the smaller one and carry on like that. I think this is good and sustainable way to go
Please, avoid using any kind of RAID0 setups - simple LVM without parity, mergefs, JBOD, etc.
With one disk failure the whole node is lost. It will be very unpleasant to have this disaster on month 15