Problem description
VMware backup appears to be stuck and does not progress for a few VM(s).
Cause:
Corrupted Virtual Disk/Snapshots: The DISKLIB-CHAIN errors are the most direct indication of a problem with the virtual disk's structure or its snapshots.
This could be due to an unclean shutdown, storage issues, or a failed snapshot operation.
Traceback:
Error Message in vixDiskLib-####.log
2025-06-24T15:11:51.839Z In(05) host-6000 2025-06-24T11:11:51.838-04:00 error -[06000] [Originator@6876 sub=DiskLib] DISKLIB-CHAIN : DiskChainDBGet: Cannot apply logicalSectorSize to partial chain.
2025-06-24T15:05:03.399Z In(05) host-5992 2025-06-24T11:05:03.399-04:00 warning -[05992] [Originator@6876 sub=vmomi.soapStub[8]] SOAP request returned HTTP failure; , >), /sdk>, method: queryNetConfig; code: 500(Internal Server Error)
Resolution:
Check vCenter Server and ESXi Host Health:
Verify that all vCenter services are running and that the ESXi host is healthy (no PSODs, no critical alarms).
Examine the Virtual Machine's Configuration:
Check for existing snapshots on the VM.
Verify the integrity of the VM's .vmdk files and their descriptor files.
Look for any recent changes or operations performed on the VM (e.g., snapshot consolidation, backup, cloning).
Investigate the Datastore:
Check the health and free space of the datastore where the VM resides.
Review other logs:
Look at the vmkernel.log, hostd.log, and vpxa.log on the ESXi host, and vpxd.log on vCenter Server for related entries around the same timestamp.
Try to consolidate snapshots:
If snapshots exist and are suspected to be the issue, attempt to consolidate them (if possible, as this error might prevent it).
VMware KB Articles:
Search VMware's knowledge base for these specific error messages (Cannot apply logicalSectorSize to partial chain, 500 Internal Server Error queryNetConfig, NfcUtil_CreateTimer: No poll loop).