What does HRESULT 0xC038005C (ERROR_VOLMGR_RAID5_NOT_SUPPORTED) mean?

ERROR_VOLMGR_RAID5_NOT_SUPPORTED

Why this is narrower than a generic disk error: volmgr raid5 not supported

ERROR_VOLMGR_RAID5_NOT_SUPPORTED has unsigned value 0xC038005C. In the volmgr layer, the operation is rejected because the current product, provider or disk set cannot create or maintain a RAID-5 plex. Diagnosis of this result should follow logical volume geometry and the disk extents that realize it through one controlled state transition.

Storage facts that change the diagnosis

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

A/B test

1. Capture the API parameters and object map that led to this result; do not begin with cleanup.
2. Build a passing control with the same disks or image copy and preserve pack and volume IDs, input structure version and sizes, transaction ID, disk-layout snapshot before the call and the first kernel storage event.
3. Run the narrow transition described here: separate plex-type validation from platform capability by testing one real RAID-5 plex and one nonparity plex on the same system.
4. Compare resulting IDs, counts, health and ownership to prove the caller crossed the result invariant rather than suppressing it.

Use ERROR_VOLMGR_PLEX_NOT_RAID5 as the nearest comparison. It is specific to the current product, provider or disk set cannot create or maintain a RAID-5 plex; 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

Separate two questions: whether the selected plex is RAID-5 and whether this Windows edition/provider can perform the requested parity operation. Record the actual plex type, disk count and provider capability so a topology mismatch is not misdiagnosed as a product limitation, or vice versa.

Corrective action and regression check

Select an operation compatible with the actual plex type and keep at least one active data copy throughout detach, repair or regeneration. The repair is incomplete until a fresh enumeration and new handle observe the corrected state.

• The original request now reaches success or a documented later status with the intended layout and access mode.
• A new enumeration reports internally consistent IDs, counts, geometry and ownership for the corrected object.
• The passing state survives the relevant lifecycle transition, such as reopen, remount, owner change or detach/attach.
• The application still distinguishes it from ERROR_VOLMGR_PLEX_NOT_RAID5 and has no unbounded retry loop.

Technical references

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