How to create bootable software raid 0 for Windows?

Question

Is there any way other than using the deprecated dynamic disk (which does not support SSD TRIM) to setup a bootable software RAID 0 with Windows 10 on a SuperMicro X11dai-N?

If so, how?

Solution 1

Intel RSTe allows booting from RAID 0 volumes. VROC is a subset of RSTe. Page 95 introduces the idea of booting from RAID, and the manual does not specify Intel drives must be used. Might work.

Solution 2

It is not currently possible to boot from a RAID 0 volume that is implemented with software.

This is a "Catch-22" situation because the disks that constitute the RAID 0 don't make sense without the software, and the software can't run without being booted.

Hardware RAID comes online when the system powers on, and therefore can be used to boot software from.

Comments

[Romen]

I don't think it's possible to use software RAID for a boot drive; The RAID drive won't be available without the software, and the software won't be running without an OS, and the OS won't be running without a drive to boot it from.

[matthias_buehlmann]

but in the windows boot process, bootmanager lives on it's own partition and is always invoked first. So couldn't bootmanager live on a non-raid partition and then load winload.exe/winload.efi from a software raid disk?

[Romen]

"So couldn't bootmanager live on a non-raid partition and then load winload.exe/winload.efi from a software raid disk?" -- It doesn't matter if you can get into the bootmanager, Windows needs to be running for that "bootable" RAID drive to come online. This is a Catch-22 situation.

[lx07]

@Romen - Software RAID 1 was/is possible - see How to set up dynamic boot partition mirroring on GUID partition table (GPT) disks in Windows Server 2008. Not RAID 0 though AFAIK.

[Romen]

@lx07, The nature of RAID 1 allows one disk to be booted by itself via the Windows boot manager. I believe in that situation the other disk comes online after the Windows kernel is booted and then the RAID is restored. Theoretically, you could boot any OS from a single drive of any RAID 1 and then begin synchronizing the disks after boot.

[matthias_buehlmann]

@romen why? Afaik in the past not all EFI bios supported ntfs, that’s why the efi partition was fat32 and bootmanager then provided the ntfs support to load winload from the ntfs partition. Shouldn’t the same work for software raid? Isn’t that what boot-start drivers are for?

[Romen]

@user1282931, I think you're missing the point. The Windows Boot Manager does not implement software RAID, therefore the virtual disk containing any EFI boot information does not exist to boot from. This has nothing to do with filesystems.

[matthias_buehlmann]

@Romen -exactly, that i understood. So question is, how can it. There is a thing such as boot-start drivers to give access to custom devices during boot. There vould also be a completely other (non microsoft) boot manager (grub?) execute winload.efi, bypassing bootmgr.efi. I don’t believe that this is fundamentally impossible

[Romen]

@user1282931, "How can it" -- It can't.

[Romen]

RTSe requires specific Intel CPUs and chipsets (Xeon, enterprise motherboards). I would argue that RSTe is not software RAID since it depends on specific hardware. This technology may still be a valid solution if the software RAID requirement is dropped.

[matthias_buehlmann]

Actually i do have a xeon-sp cpu and intelC621 chipset, but my mainboard manual doesn’t mention anything about rste - probably because it uses vroc for raid. I can’t use vroc but vroc isn’t applicable in my case, that’s why i look for a software solution

[matthias_buehlmann]

SuperMicro X11dai-N. It has vroc only on two oculink ports, not on the other pci-e ports and also my M.2 SSDs aren’t intel

[matthias_buehlmann]

Again - the firmware does not need to understand the raid - only bootmanager (living on a non-raid partition) has to know how to read the software raid

[harrymc]

Read again my answer that you downvoted. You don't understand UEFI boot, and until you do, you may multiply posts here but never get an answer that suits your ideas.

[matthias_buehlmann]

You said it in your answer yourself: “This means that the firmware needs to incorporate drivers for all the disks on which are placed boot-managers.” that is correct - it needs to be able to load the bootmanager. But if that bootmanager knows how to do raid, it can happily access the raid-0 system partition then.

[matthias_buehlmann]

Bootmanager and system don’t need to be on the same partition or even same disk.

[matthias_buehlmann]

To your edit - yes for my SATA drives veoc works perfectly. But for nvme other rules apply unfortunately. 1st: for raid-0 on non intel drives, a hardware dongle is required. 2nd the X11dai-N exposes the required VMD only on the two oculink ports. My 4 nvme’s are connected through the pci-e ports however. That’s why I can’t use vroc for the nvmes

[harrymc]

Right, which is why you need a non-RAID disk to load the bootmanager from, and then it takes over. But the Windows bootmanager does not reside in the EFI partition, which is perhaps where is your misunderstanding. You get a chicken-and-the-egg paradox, where the firmware needs Windows to understand the RAID, but the Windows bootmanager needs the firmware to be read into memory.

[matthias_buehlmann]

Incorrect, windows bootmanager resides in EFI/Microsoft/Boot

[matthias_buehlmann]

There really is no chicken-egg

[matthias_buehlmann]

I still don’t see how this is a catch-22: [UEFI]—starts bootmgr.efi—>[singledisk FAT with superbootmgr.efi]—starts winload.efi—>[RAID-0 array containing winload.efi and windows]

[Romen]

@user1282931, You can't boot twice; You either have a hardware RAID and can boot from it, or you don't have a hardware RAID and can't boot from a volume that doesn't exist until booting.

[Romen]

@user1282931, You are assuming that the windows bootmanager can bring a software RAID online. It can't.

[matthias_buehlmann]

But What prevents some bootmgr.efi implementing raid logic and residing on non-raid disc to load winload.efi from a raid disc?

[matthias_buehlmann]

“You are assuming that the windows bootmanager can bring a software RAID online. It can't.” I assume that either windows boot manager with special boot-start drivers can do that or some third-party bootmanager can do it

[Romen]

"But What prevents some bootmgr.efi implementing raid logic" -- Software-based RAID requires an on-going process to provide a virtualized disk. This process can only be useful when running in an OS because a boot manager does not continue to execute in the background after booting an OS.

[harrymc]

Last try: There is only one bootmanager - the UEFI. The rest are only bootloaders. The tiny software in the EFI, that Wikipedia calls "stubs", are only small extensions to the UEFI and their purpose is to locate, load and execute the real kernel bootloader. They use UEFI services so are dependent upon it. The fact is that the 100MB EFI partition is too small to contain the Windows kernel and several dozens of Linux kernels, so it only has stubs that are not even as functional as the old-style BIOS.