How robust is two-way mirrored storage spaces in Windows? Are there any common gotchas?

Question

I'm running Windows 10 Pro and have set up a Storage Pool with 3+3+6+6+6=24 TB with a two-way mirroring configuration. I've done this so that if one of the disks fail I can add a new one to compensate. That said, I'm not entirely sure if I've done it correctly - mostly because it was "too easy".

My setup is as follows:

And the storage space is configured as follows:

If I fill this drive to the brink, will redundancy still hold? If a disk fails, is it as easy as just adding a new one of same or larger size?

Answer 1

How robust is two-way mirrored storage spaces?

This configuration seems to be just as robust as a RAID configuration in terms of data redundancy, hot swapping, expanding, etc. functionality wise.

If you leverage the ReFS file system type with your storage spaces, then you further increase the resiliency of your data written on the disks.

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If I fill this drive to the brink, will redundancy still hold?

The storage pool manages the group of disks in an array and is smart enough to figure out how to distribute data written to the disks (including mirror copies) to ensure optimal usage.

Filling up any disk partition to full capacity is never a good thing since once it is filled and a new write operation comes in then you will start having problems.

You will still need to manage and monitor the disk usage, and routinely to take proactive measures such as adding a disk to the pool with expand operations, etc.

Start testing the functionality now while it's not urgent to confirm and document the procedure in detail so you have a good understanding but it should be "simple" for you just like you say it seems.

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Test Disk Operations

While you can, and before you start putting critical data on the storage space, do some testing and confirm that it works as simple as it is supposed to. This should be simple to test and document the process so you know what to do later down the road once time has passed and it's time to replace a failed drive, etc. when it's a little more critical—you can thank yourself then for doing this now.

I would have a couple hot spare drives on site with the two-way mirror configuration since if one dies, time is critical to get a new one added and rebuilt to ensure continued data redundancy.

Data Backups - Common Misconception

It is important to understand that data redundancy should not be used as a data backup solution and that backing up data on systems with redundant drives is still a best practice. This is especially even more important if your data is critical to you and/or your business.

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Further Resources

• Storage Spaces in Windows 10 - Step Details
• How to Use Windows 10’s Storage Spaces to Mirror and Combine Drives

• Does ReFS replace NTFS? When should I use it?

• Windows Storage Spaces and ReFS: Is it time to ditch RAID for good?