I am looking to dual boot Fedora 40 with Windows 11 on a Dell XPS 13. I have reading conflicting advice about the need to disable RST before installing Linux. This is the information provided by Ubuntu.
Can anyone tell me whether I need to disable raid before installing Fedora? I have managed to boot Fedora 40 from USB without any difficulty.
Depending upon the hardware and the version of fedora being installed it may be necessary to disable rst. It also may be necessary to switch the sata settings from RAID to AHCI. This is up to testing to determine which is required.
Some open the bios settings and make the switch then boot into windows to ensure that windows can still boot (and make repairs if needed) before installing fedora.
You’ll very likely have to, but if you want to know for sure, leave it enabled and boot a Linux LiveUSB, and see if you can see drive(s).
In my case with Coffee Lake, my NVMe doesn’t show up at all with RST enabled and dmesg shows something about port remapping. There’s probably something to make it show with RST enabled, but it was determined by someone with reason(s) to make it not appear by-default, and RST does nothing beneficial in this set-up since it’s still AHCI; hence disabling it and going with AHCI makes sense 
I had a XPS 13 at some point and also went with using AHCI Windows and Linux.
Also with my NVMe currently, using RST only allows the NVMe to be visible at all when it’s in 512e sector mode. When it’s on native 4K sector mode, not even BIOS sees it with RST. That implies RST (at least on my set-up) is for Legacy applications.
I can do 4K sectors fine Windows and Linux with AHCI.
Yo do need to disable raid, but if Windows was installed with raid, you need to reconfigure it to boot with AHCI before disabling raid in “BIOS”: