After several weeks of hard work I have finally given up on building RAID1 array on my new home PC.
Previously I had a fairly old but still good PC built on MSI X58 chipset and i7 CPU. The motherboard had an inbuilt RAID controller so I have built RAID1 and forgotten about it completely. As with any normal old-school RAID1 I was able to swap HDD’s, replace them and even clone them by building the mirror, breaking it and replacing the drive.
Everything has changed when I have built a new gaming machine based on MSI B350 motherboard. This motherboard comes with onboard RAID too, however this RAID uses some closed proprietary standard and the “raided” disk attached to another system looks like a disk with a single partition and zero volumes. It is absolutely unreadable unless you connect it back to MSI RAID. There is no “break mirror” option either. More to that, when I had a faulty SATA cable and one disk became defunct, after restoring the functionality MSI RAID was unable to rebuild the mirror. I spent 3 weeks communicating with MSI support and their verdict was: make a full backup, clean up the RAID, rebuild it, rebuild and restore your machine. Thank you very much, MSI, but where is my data protection?
I went with software driven RAID then and used this workaround provided by Microsoft. This workaround works, however after each reboot Microsoft Mirror set fails and needs to be resynchronised. Turns out this is a known problem(!!!), which persists since Windows 2008 Server era and is still not fixed in Server 2019 or Windows 10.
Verdict: there is no way to provide data protection to home PC using software RAID. Modern MSI RAID should not be used either because it is a big problem, not a solution. Maybe RAIDs from other vendors are better. Keep your system simple and rely only on regular full backups to the second drive or external media.