I’ve run into a problem installing Fedora after Windows 11 for a Dual-Boot environment on my HP Z840 Workstation. Although Fedora recognised other drives on the system, my Windows drive and its remaining space did not show up. This was a Samsung EVO 970 drive I had left about half un-allocated for the Linux installation. Neither GRUB nor the Fedora live system saw the partitions.
Turns out that this is caused by a BIOS setting: there’s a default device setting for the SATA controller that’s set to RAID (under Advanced – Device Configurations). Other options here are AHCI and IDE. As it happens, RAID will prevent Linux distros from seeing M2 drives – for whatever reason. Switching this to AHCI solved the problem.
Thanks to kahupaa on Reddit for this tip!