@stormi no, the disk pair contains an old installation of XenServer (no raid) and I do not think it has ever been used for anything else... md5sum of the ISO: deb2a0990390a6a4eb51a428b6a53995 (the same as the one shown here!).
I'm not quite inside the xen logic, but on dom0 I do not find any trace of the availability of raid software profiles ... I figured I could find something with "dmesg | grep md" ... sure I'm not forgetting some boot options?
Drastic!
There must be a pro, otherwise the market is really bastard to propose this raid of the poor... 
I have never found the time to fully evaluate the performances and the risks, but I have dozens of them up without collecting difficulties... I will try to deepen, even to sleep without worries 
.
So,
I tried the ISO but I am not able to create the volume with the softraid; I do not understand where I'm wrong but after choosing the volumes the screen remains blue and does not continue the installation even waiting for minutes...
What I see:
....
mdadm: Unrecognised md component device - /dev/sda
...
mdadm: Unrecognised md component device - /dev/sdb
I tried with the various options (install, safe, multipath) but none seems to go; and I can not understand where I'm wrong.
PS: The installation test is performed on non-empty disks, where there is a partitioning and an old installation of XenServer 6.2. I have not tried to wipe the disks, I would first understand if I do not skip a few steps...
Thanks,
Arturo.
Re: An updated installer for XCP-ng 7.5.0
Interesting,
I try but I wonder if we can handle hybrid situations...
If the server has software RAID controllers such as LSI MegaRAID via Intel chips and the possibility to change from BIOS between AHCI and RAID mode, how to proceed to better use the hardware? I would like to understand how to let xcp-ng recognize the raid controller (ie how to load the megasr drive and complete the software raid with the plus of the hardware part).
Thanks,
Arturo.