The most possible reason is that the drive is not “clean”. To be available for storage spaces, the disk shouldn’t have any volume or partition on it and better be a raw drive.
Please provide more information:
- Is there any change before the problem happened? Such as hardware replacement, and software installation?
- Is there any 3rd party protection/anti-virus tool?
- Please check the System event in Event Viewer to confirm if there is any related event has been logged.
If you run Reset-PhysicalDisk on a physical disk that appears as lost communication or split, it attempts to re-integrate the disk into the storage pool if the target disk is discoverable. After resetting the disk, use Repair-VirtualDisk to recover its resiliency.
If you run Reset-PhysicalDisk on a disk that isn’t a part of a storage pool, it will clear any lingering storage space data and metadata on the disk.
Hope this resolves your Query !!
--If the reply is helpful, please Upvote and Accept it as an answer–
problem is solved.
first, Removed-VirtualDisk, then
3 disks in the pool listed in Get-PhysicalDisk AND CanPool=True, one other disk was marked in Disk Management as still in the non-existent pool and also didn't show in Get-PhysicalDisk. then i used DiskPart to Clean it and then it showed in Get-PhysicalDisk & CanPool=True. then i rebuilt the pool and restored the backed up data.
i'm thinking while the pool was alive any disks previously attached were protected. the protection was giving me a pain.