Usually when I come across a system like this, Ijust flash the firmware to an IT mode so we get just an AHCI system with JBOD, but sometimes it is not practical for remote systems or if we fear that flashing is too risky if something goes wrong.
In this case, we unfortunately have to use LSI/Broadcom proprietary CLI tools (megacli) to even make the drives visible.
Step 1 - Download MegaCLI
The official broadcom packages lack .deb packages and only have .rpm for........
This sometimes happens when trying to install the EFIversion of grub to a device when you are booted into Legacy/MBR mode. It doesn't seem to occur on all machines, but some and seems somewhat BIOS dependent.
grub-install --target=x86_64-efi /dev/sda
Installing for x86_64-efi platform.
grub-install.real: warning: Couldn't find physical volume `(null)'. Some modules may be missing from core image..
grub-install.real: warning: Couldn't find physica........