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Hello, everybody,

I'm testing a scenario and reaching my limits somewhere. I am currently playing with a VM with two virtual hard disks of 35GB each. Here I installed Windows Server 2019 Standard. I have set up a mirror for hard disk C via the disk management. The system automatically converted both disks into dynamic disks. If I now remove the main hard disk during operation (boot partition), the system first runs as usual and then reboots. Here I didn't manage to get the system up and running again with the Windows Server installation ISO. What do you have to do to run Software Raid 1 to get the system up and running again after a crash? Is it possible to create a recovery boot image etc.?

I know that raid with a raid card is the more reasonable choice, but I would like to do that with the software raid and hope someone can help me here.

Many thanks in advance!

It is not intended by Microsoft and Microsoft has been advising against dynamic media for some time, especially if the system partition is located on it. In addition, Windows does not store everything necessary to reboot a system on the second disk. With EFI systems, there is also the EFI partition, which Windows cannot mirror, but which must be manually transferred to the second disk and kept up to date there. Of course you can do some tinkering, but the Windows software RAID was never designed to protect the system partition. To secure the system partition you have to use a RAID card or the RAID function of many current motherboard chipsets.

Hello and thank you for your answer.

Is it possible for me to switch to RAID 1 Mainboard RAID 1 for an already installed Windows system without having to reinstall the system? I think that the problem will be that the RAID drivers are missing from the motherboard and the system will not boot.

I had noticed some time ago that you have to change values in the registry before you switch to RAID 1 while Windows is running so that AHCI is activated. Then change the BIOS to RAID 1 and it should work or am I wrong?

Greetings

One possibility would be to first mount another (non-boot) drive as RAID. Windows will install the required drivers and mark them as critical for system startup. This procedure is recommended e.g. for VMware to move to PVscsi - these are also drivers that Windows does not bring along itself. Afterwards Windows "knows" the drivers and loads them even after the migration of the boot disk.