Your son already knew.
When my daughter was 4 I asked her to say all the bad words she knew. She started with the not so bad ones and ended with all the worst ones.
I guess the other kids in her kindergarten had older siblings, so she knew them all already. But most importantly, she also knew when to use them and when not to use them. :)
My own approach is to run vm/lxc of SSDs that's are hosted on proxmox directly.
Then I have a truenas with Nas storage. I mount that through SMB to proxmox and pass the different dirs into the vm/lxc that need them.
SSD are much better performance for vm/lxc.
Edit: even running the Nas as a vm i would mount it with SMB, making it easy to spilt them up later if you want. Also I have 10gbit netcards between the nas and proxmox.