Thanks for your reply much appreciated.
It is going to be (eventually) a production system and I’m very familiar with mongodb, and pretty familiar with Linux in general just less so with the particular commands I need to mount a different filesystem.
I’m happy to use XFS as the only file system if that’s easy to do and I’m setting up everything from scratch anyway so no problem there.
Thanks for the pointers - can you clarify if I can use fdisk/gdisk to use XFS for the entire file system?