What does HRESULT 0xC038005B (ERROR_VOLMGR_MIRROR_NOT_SUPPORTED) mean?

ERROR_VOLMGR_MIRROR_NOT_SUPPORTED

What this result says about the disk model: volmgr mirror not supported

The practical meaning of ERROR_VOLMGR_MIRROR_NOT_SUPPORTED (0xC038005B) is tied to logical volume geometry and the disk extents that realize it: the current product, provider or disk layout cannot create or maintain mirrored plexes. The result does not, by itself, prove file-system corruption or physical-media failure.

Diagnosis of this result should begin with the object model and generation current at the failure. A later successful enumeration may describe a replacement object and cannot retroactively validate the rejected request.

Capture the exact object instance

Prove the condition in a test volume

1. Associate this result with one caller, one transaction and one target UniqueId.
2. Save the pre-call and post-call inventories, including pack and volume IDs, input structure version and sizes, transaction ID, disk-layout snapshot before the call and the first kernel storage event.
3. Use this A/B case without touching unrelated storage: serialize the exact VM_VOLUME_LAYOUT buffer, validate every count and Size field, and compare it with a layout produced by a known-good management API.
4. Validate both the HRESULT and the on-disk or provider state after the relevant reopen, remount or attach cycle.

The distinction from ERROR_VOLMGR_UNEXPECTED_DISK_LAYOUT_CHANGE is operational. The current product, provider or disk layout cannot create or maintain mirrored plexes; log the neighboring code separately so capability, identity and state are not conflated.

Mechanism-specific note

Capability depends on product edition, provider and the selected disk set. Record the provider and intended disk geometry before assuming a transient failure. A platform capability result is different from selecting a nonmirrored plex for a mirror-only operation, and the remediation should not conflate those cases.

Safe recovery path

Select an operation compatible with the actual plex type and keep at least one active data copy throughout detach, repair or regeneration. Apply the change through the supported storage API, then close and reacquire affected objects before retrying.

• The controlled A/B case changes only the invariant that triggers this result.
• No unrelated disk, cluster owner, tier policy or virtual-disk backing file is altered to hide it.
• Health, synchronization or job state reaches a terminal value consistent with the repaired operation.
• Telemetry includes both symbolic names when it or ERROR_VOLMGR_UNEXPECTED_DISK_LAYOUT_CHANGE occurs again.

Technical references

• Microsoft: COM error codes for VOLMGR, VHD and SDIAG — use this source to verify volmgr state and parameters.
• Microsoft: Virtual Disk Service object model — documents the supported management path relevant to this HRESULT.
• Microsoft: Pack object — defines the volmgr objects used to interpret it.
• Microsoft: Virtual Disk Service common return codes — primary API or object-model reference.