Conserving or Minimizing Disk Space on ASP 1 (SYSBAS) when Using Independent ASPs (iASPs)

***IBM i playground questions***

I am doing testing on IBM i client partitions that will hold all user/app
data in independent ASPs (iASPs).
The goal is to contain all library and IFS data on iASPs, while the Load
Source and SYSBAS remain on ASP 1.
I'd like to condense multiple development and testing areas onto one LPAR,
while still giving each environment a dedicated space to work in via
separate iASPs.
(Whether this is feasible/preferred over separate LPARs is another
discussion.
Feel free to chime in on that point though.)

If minimum Load Source rules are followed, I would use 40GB for the disk.
Multiply that by 6 disks and you've got 240GB.
If I give myself headroom, I could use 80GB. Over 6 disks, this equals
480GB.
(Mind you, I'm assuming best practice is to keep all the disks the same
size.)

I already asked IBM these questions, and in a nutshell, they said, "It
depends".

Questions:
1. How much headroom do you all like to allocate for the LS disk size so as
not to box yourselves in?
2. In a scenario such as the one described above, do you feel that
allocating between 240GB-480GB
is overkill for ASP 1 if all user and app data will be stored in iASPs?

Maybe I'm just being stingy with storage.

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Jacob
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