Two drives in a mirror keep working when one dies. Storage Spaces builds that inside Windows, and its panel is honest about problems if you read it.
Create a **pool** from two empty drives, add a **two-way mirror** volume and check the health panel monthly. A mirror survives a dead disk, never a deleted file.
Joining a disk to a pool wipes it. Copy anything you need elsewhere, then confirm in Disk Management that both drives show as unallocated and carry no letter you still use.
diskmgmt.mscThe Storage Spaces page lists physical drives and offers to pool them. Two drives of the same size keep the arithmetic simple; mixed sizes work, but usable capacity follows the smaller disk.
Control Panel > Storage Spaces > Create a new poolA two-way mirror keeps one copy on each drive and survives a single failure. Three-way exists for servers; at home it doubles the cost for a second failure you are unlikely to meet.
Resiliency: Two-way mirrorThe volume appears as a normal drive letter. Move the library or the project folder onto it and leave the system drive alone; a mirrored data volume does nothing for Windows itself.
Shut down, unplug one drive and boot. The panel should report the pool as degraded, the files should still open, and the warning should name the missing disk. Plug it back in and the pool repairs.
Remove the failed drive from the pool, attach the replacement and add it, then run repair. Rebuilding a large mirror takes hours, and the volume stays usable but slower while it runs.
Storage Spaces > Physical drives > Remove / AddA drive came back late, often behind a USB enclosure. Give it a minute before you remove anything from the pool.
The pool is repairing, or the remaining disks cannot hold the volume. Wait for the repair, then retry.
Expected for a mirror; every write goes to both drives. Read speed stays the same.
Pool metadata is damaged. Do not format. Check the state of the pool in the panel first and only then decide.
A mirror for a dead disk, a backup for everything else. Ransomware encrypts both halves at once.
Yes, but usable capacity is twice the smaller disk and the rest of the larger one is wasted.
Delete the volume in **Control Panel > Storage Spaces**, then remove both physical drives from the pool and format them in Disk Management. The data on the volume is gone at that point, so copy it first.
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