Re: Raid question on expanding array size
This question ist very offtopic.
You do not need a 64 bit linux to access disk drives beyond 2 TiByte. Maybe you are confusing Tera (~ 2^40) with Giga (~ 2^30)? Anyway, disk accesses have been 64 bit addressable for ages in linux on 32 bit architecures.
There is no way I am aware of to exent a raid 0, besides backp and recreate. I am pretty sure it can't be done because of the way the data is striped accross the two drives.