What does HRESULT 0xC038004A (ERROR_VOLMGR_VOLUME_NOT_RETAINED) mean?

ERROR_VOLMGR_VOLUME_NOT_RETAINED

Identify the owner before touching the layout: volmgr volume not retained

The practical meaning of ERROR_VOLMGR_VOLUME_NOT_RETAINED (0xC038004A) is tied to logical volume geometry and the disk extents that realize it: the volume has no retained partition record to remove, restore or query. 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.

Minimum diagnostic set

A management layer handling this result should report later recovery errors separately, because they answer a different question from the failed storage operation.

Reproduce without destructive cleanup

1. Create a nonproduction case that preserves the same geometry and ownership model.
2. Collect volume ID, requested length, sector sizes, extent table, plex/member counts, disk health and the exact VM_VOLUME_LAYOUT buffer before invoking the first mutating API.
3. Re-enumerate after the transition and confirm this result is not reproduced by a stale handle from the old generation.

Use ERROR_VOLMGR_VOLUME_RETAINED as the nearest comparison. It is specific to the volume has no retained partition record to remove, restore or query; the neighboring result belongs to another validation or lifecycle branch. Keeping both names prevents a generic storage label from hiding the actual owner.

Mechanism-specific note

Retain-partition state records whether partition identity should survive deletion of the dynamic volume. Query the flag and the partition record together. It is not a general “keep data” switch, and toggling it cannot repair missing extents, synchronization failures or an invalid pack log.

Restore the contract

Refresh the disk layout, serialize the change as one volume-manager transaction and reject any external partition mutation until commit or rollback completes. Apply the change through the supported storage API, then close and reacquire affected objects before retrying.

• the first retry uses newly enumerated identifiers rather than cached handles.
• The durable metadata or provider state agrees with the success returned after it.
• A second run after close/reopen does not recreate the rejected condition.
• the nearby ERROR_VOLMGR_VOLUME_RETAINED path remains separately testable and separately logged.

Do not use it as a reason to edit dynamic-disk sectors, VHDX metadata, RCT sidecars or snapshot support files directly. Unsupported edits can turn a recoverable state mismatch into persistent corruption.

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.