Create a storage space (software RAID: RAID 0, RAID 1, RAID 5 or RAID 11) on Windows 8 to 11

5. Two-way mirror storage space (software RAID 1)

5.1. Create a two-way mirror storage space (RAID 1)

With Windows storage spaces, you have the option to improve only the security of your data (with at least 2 physical disks) by keeping an up-to-date copy of your disk in real time.
Which protects you against the loss of a physical disk.

To do this, Windows will create a software RAID 1. This consists of writing exactly the same data on 2 physical disks.
Thus, in the event of a physical disk failure, you will not lose any data.

To create a two-way mirror storage space (RAID 1), click on the "Create a new pool and a new storage space" link.

Warning : this doesn't protect you against errors that could occur in the file system or against viruses or even ransomware that could render your data unusable.

As explained above, a two-way mirror storage (RAID 1) requires 2 physical disks.
Select the 2 physical disks to use for this new storage space and click "Create pool".

Note: if the desired physical disks do not appear here, refer to step 1 of this tutorial to fix the problem.

In the "Create storage space" window, configure at least these options:

• Name: RAID 1 storage (for example).
• Resilience type: Two-way mirror.
  As stated by Windows, this type of resilience writes 2 copies of your data and requires at least 2 physical disks.

Then, click on "Create storage space".

Your new storage pool (with 2 physical disks) and your new "RAID 1 storage" storage space appear.

If you open file explorer and go to "This PC" you will see your new "RAID 1 storage" storage space appear.

In disk management (accessible via a right-click "Manage" on "This PC"), you will see that your new "RAID 1 storage" storage space appears as a local disk instead of the physical disks of which it is composed.

Store data in this "RAID 1 storage" as if it were a regular volume (partition).

Then, go back to the "Storage Spaces" window and you will see that the percentage used on each disk will have increased and is identical for each disk.
Which is normal since the same data is stored on the 2 physical disks that are members of this two-way mirror storage.

5.2. Data preserved in case of physical disk failure with two-way mirror storage (RAID 1)

If a physical disk used for your two-way mirror storage (RAID 1) fails, its status will change to "Warning" and the status of the failed physical disk will also be "Warning".
This is because, as Windows tells you, the resilience has been reduced.

Plain Text

Two-way mirror storage.
Warning: Reduced resiliency; check the Physical drives section.

If you go to file explorer, you will still see your storage as "RAID 1 storage".

As expected, the files there still appear.

You can try to copy files there to another location.

As expected, the files in your dual mirror storage (RAID 1) are therefore still usable without any problems.

If the error is caused by a physical disk that you had simply temporarily unplugged, then simply plug it back in and Windows will automatically detect it.

For storage visible in file explorer, it still appears there and is still functional.

5.3. Delete a two-way mirror storage space (RAID 1) and its storage pool

To delete a two-way mirror storage space (RAID 1) and its storage pool, start by deleting the desired storage space.
To do this, in the "Storage space" section, click on the "Remove" link located to the right of your "RAID 1 storage" storage space of type "Two-way mirror".

Deleting this "RAID 1 storage" storage space will permanently delete the data contained therein.
Confirm the deletion by clicking on "Delete storage space".

Please wait while the storage space is deleted.

The deleted storage space disappears.
Now, also delete the unused disk pool so that you can reuse your physical disks later from the Windows "Disk Management" console.

To do this, click on "Delete pool".

Confirm the deletion of your storage pool by clicking "Delete pool".

Once the pool is deleted, you will see your corresponding physical disks again in Windows disk management.