Create RAID 1 on Windows 10

Question

Usually I work with RAID controllers however in this case this is not possible so I need to use the "Windows software raid" (or some other kind of software raid for that matter).

If I have two SDDs (same size) in the PC and one of them configured as a basic disk (GPT) already containing the operating system (Windows 10 with standard partitioning: EFI,MAIN,RECOVERY, it's just one main partition with OS and all the data) is it still possible to create a RAID 1? The only possibilities I found required the system disk being a part of an disk array BEFORE it received any data or not being part of the RAID at all (using either "Windows pools" or "dynamic disks and mirrored volumes").

Is there any work around or is it generally not possible to mirror the system partition without hardware raid?

The goal is to have redundancy on my laptop while unable to make a data sync to the cloud or an external hard drive (in case the SSD fails) without the help of a HW raid controller.

Update: I tried FreeFileSync but it gives me too much of a hassle permanently complaining that it can't sync certain files. I would rather have it just try to sync the file if it doesn't work just put them on a list automatically and continue with the next file so at least I know what I didn't sync in case s.th. fails.

Answer 1

You can't set up RAID on a disk without discarding its contents, because setting up RAID typically involves setting up appropriate structures on the disk. Some of the existing data would be overwritten, thus destroying the partition table.

The workaround would be to image the disk, set up RAID and restore the image. The system must be prepared to boot from RAID before imaging though. Otherwise it won't boot, obviously. I'm not sure how doable this is on Windows.

To mirror entire disk including the boot volume, you'd have to use the misleadingly called "fake RAID", ie. software RAID solution with booting support built into motherboard firmware. Intel's implementation is called Rapid Storage Technology, typically shortened IRST or just RST.

(The following part of the answer was written before the mention of "backup" was removed from the question. I'm leaving it here for future visitors for whom it may be relevant.)

But!

This is not what you need. You need a backup. RAID is not a backup.

All RAID1 does is keeping the system operational when one of the drives fails.

It won't protect you in case of:

• power supply failure that sends a voltage spike to the motherboard and fries both drives
• random bit flip corrupting data on one drive^[1]
• RAM failure corrupting data on both drives
• fire destroying entire laptop
• ransomware encrypting your files
• you realizing that you've deleted a very important file 2 months ago

You need a proper backup strategy.

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^[1] You need at least 2 drives of redundancy to detect which drive is the corrupted one. Some filesystems with built-in checksumming and LVMs (ZFS, btrfs) can do this with just one drive. There's also dm-integrity for Linux.