How much trilobites are in one trilobyte? (E-shop with funny t-shirts - in Czech language only)
There will be solutions for some problems I was unable to google.
Server IBM x3550 M3 7944K1G isn't able to boot installed Linux from HDD. Boot from CD/DVD and USB flash works. The only message is string "Failed". There is UEFI, no BIOS.
Lots experiments with ELILO didn't succeeded.
But after the server tries all UEFI devices, it offers Ctrl-H for menu of SAS BIOS. There is possibility to make HDD bootable in that menu.
Then the server boots grub after it fails on all UEFI devices and waits for SAS BIOS. It needs some time, but the boot is incredibly slow and time between start and try to boot from the first UEFI device is longer than additional time to real boot.
It boots via some legacy/BIOS emulation way probably, but it's not problem (it seems).