VMDK or VMware Snapshot Chain Damaged
A VMware virtual disk may fail to open when its descriptor, flat extent, delta disk, parent reference, or snapshot sequence no longer agrees. The guest data may span several files, so treating one visible VMDK as the complete disk can produce an incomplete or outdated result.
Do not delete snapshots, consolidate by trial and error, edit parent references on the only copy, or flatten files back onto the affected datastore. Preserve every descriptor, extent, delta, and VM configuration file.
What this condition means
A snapshot chain records parent-child relationships between virtual-disk states. Missing descriptors, renamed files, incomplete delta extents, datastore corruption, or recovery from an older storage state can break that relationship.
The newest timestamp is not automatically the correct endpoint. The chain must agree on identifiers, parent references, grain metadata, capacity, and readable coverage before guest filesystems are interpreted.
What to record
- VMware product and version
- Complete VM directory listing with names, sizes, and timestamps
- Every VMDK descriptor, flat extent, delta, sesparse, snapshot, and VMX file
- Snapshot and consolidation history
- Datastore, RAID, restore, copy, rename, or manual descriptor actions already attempted
What not to do
- Delete snapshots or choose “Consolidate” on the only copy
- Rename or edit VMDK files by guesswork
- Attach uncertain deltas to a production VM
- Clone back onto the affected datastore
- Assume a VM that boots contains the latest application data
How ADR evaluates it
ADR inventories the complete virtual-disk set, validates descriptors and parent relationships, and checks which extents remain readable before selecting a reconstruction path.
Work proceeds from protected copies. Candidate virtual disks are checked at the guest filesystem, database, and priority-file level rather than judged only by whether VMware accepts them.
What happens next
Broken snapshot relationships are often recoverable when the required extents remain available. The outcome depends on which files are missing or damaged and whether consolidation or overwrite attempts changed them.