New Installation of Leap 42.2 Advice on Partitioning Please.

I have been so pleased with 42.2 on my workstation I want to install it on my older backup machine.

The drives are set up as two RAID arrays, sda is about 450 GiB and sdb is 2.27TiB. The large drive is used for multimedia.
What I am thinking is all the OS on sda and just format sdb for /multimedia directory with simlink? to my /home directory. I want to use BtrFS for my root directory which I will make 50 GiB.
A couple of question:-

Do the bunch of subdirectories you get with BtrFS get created automatically and do they use part of the 50GiB or part of the rest of the partition?

What file systems should I use for /home on sda and for the whole of sdb?

Grateful for thoughts and advice please.

Budgie2

You indicate RAID but you seem to only have 2 drives with different capacities. So I think you need to explain more since RAID is best done and normally with matched drives… If you use true hardware RAID then I’d expect 4 drives two of each size and they would show up as 2 drives to the system. But with FAKE or software RAID that is not how things show. Soooo…What you got??

With a normal install all the sub volumes/directories are created. You don’t have to do anything special. The sub volumes are mostly to control the snapper stuff since not all files are normally snapshot. Sub-volumes are not pre allocated space they just use the pool from root

Default is XFS which is fine Personally I still use ext4 for root and home

Hi and thanks for the reply. All RAID arrays are hardware arrays. As I recall there are 5 identical drives in RAID 6 array giving the 2.27TiB and 3 identical drives in RAID 1 array with a hot spare.
All looks now to be academic as there seems to be a recurrence of a mobo fault due to poor quality electrolytic capacitors failing. Thought I had it fixed but had relegated the machine and replaced it with newer machine. Hoped to bring old one back to life but now shall use drives in a NAS and scrap the chassis.

Other points noted and thanks for the advice.
Regards,
Budgie2