Hello,

I am trying to install Devuan {Beowulf server (CD), Chimaera minimal
(USB)} on the above machine. It has a 100M EFI partition 1, W10
(partition 2, 116G, shrunk from 370G), [vacated free space for linux
after shrinking, ~250G], and a Windows recovery partition 5 (~520M). The
machine boots Windows 10 reliably with UEFI. I would like to keep the
W10 installation if possible.

However, despite two days of effort, I cannot get the machine to boot
linux from the hard drive. The first problem was not detecting disks
during installation, although after switching to legacy boot, the
installer found the disks; partitioning and installation then completed
as expected. The machine, however, failed to boot (no bootable image)
after this 'successful' installation. I grub-installed to the
'removable media path' as advised,, but I did use a 'targeted' not a
'generic' initrd; this last has not been a problem before.

I have disabled the RAID according to these instructions.

https://www.dell.com/community/PowerEdge-HDD-SCSI-RAID/Linux-installation-doesn-t-find-physical-disks-on-R320/td-p/7659439

The BIOS reports that there are no hard drives present, despite being
able to boot Windows. I have tried to add boot devices to the UEFI
menu, I can add the DVD drive, and boot from the Beowulf CD, which
then fails at the detect disks stage; I can add the USB, but it doesn't
launch the installer. I am also given a list of 3 or 4 entries (which
look like they might be partitions, although they are all identical),
although adding them causes either an 'Input not supported' error or
a 'no bootable device found'. I have changed the SATA controller from
RAID to AHCI. Is there anything that I've missed?

This is a newly-purchased, refurbished machine, and so I don't really
want to open the case, just in case something is broken (although I
can't think what) and under warrenty (unlikely). But as a last resort,
what would happen if I removed the RAID card and connected the two
drives as SATA? Would the BIOS then manage this automagically? Is there
a master (independent) BIOS image stored on the motherboard, with a
lesser one on the controller, and configured independently via the F12 menu.

Many thanks, sorry for the amount of text

fraser