Third party backup fail to consolidate snapshot files

Products

• VMware vCenter Server
• VMware vSphere ESXi

Issue/Introduction

• Thid party backup fail to consolidate snapshot file
• A backup is completed successfully, however the consolidation is not performed correctly due to file locks
• On the ESXi host validate the vmkernel log (/var/run/log/vmkernel.log):
  

  yyyy-mm-ddThh:mm.ss.xxxZ In(182) vmkernel: cpu6:2110410)FSS: 6835: Conflict between buffered and unbuffered open (file 'vmname-flat.vmdk'):flags 0x4002, requested flags 0x8
  yyyy-mm-ddThh:mm.ss.xxxZ In(182) vmkernel: cpu6:2110410)FSS: 6835: Conflict between buffered and unbuffered open (file 'vmname-flat.vmdk'):flags 0x4002, requested flags 0x8
  yyyy-mm-ddThh:mm.ss.xxxZ In(182) vmkernel: cpu6:2110410)FSS: 6835: Conflict between buffered and unbuffered open (file 'vmname-flat.vmdk'):flags 0x4002, requested flags 0x8
  yyyy-mm-ddThh:mm.ss.xxxZ In(182) vmkernel: cpu6:2110410)FSS: 6835: Conflict between buffered and unbuffered open (file 'vmname-flat.vmdk'):flags 0x4002, requested flags 0x8
  

• hostd.log(/var/run/log/hostd.log) :
  

  yyyy-mm-ddThh:mm.ss.xxxZ Db(167) Hostd[2100508]: [Originator@6876 sub=Vigor.Vmsvc.vm:/vmfs/volumes/datastore/vmname/vmname.vmx] Consolidate Disks message: An error occurred while consolidating disks: Failed to lock the file.
  yyyy-mm-ddThh:mm.ss.xxxZ Db(167) Hostd[2100133]: --> Locking conflict for file "/vmfs/volumes/datastore/vmname/vmname-flat.vmdk". VMFS on-disk lock owner is host with MAC address xxxxxxxx-xxxxxxxx-xxxx-xxxxxxxxxxxx and VMFS lock mode 0x2.
  yyyy-mm-ddThh:mm.ss.xxxZ Db(167) Hostd[2100133]: --> Locking conflict for file "/vmfs/volumes/datastore/vmname/vmname-flat.vmdk". Kernel open flags are 0x4002. Owner process on this host is world ID 2110410 with world name vmx-vcpu-0:vmname.
  yyyy-mm-ddThh:mm.ss.xxxZ Db(167) Hostd[2100133]: --> Consolidation failed for disk node 'scsi0:1': Failed to lock the file.
  yyyy-mm-ddThh:mm.ss.xxxZ Db(167) Hostd[2100133]: -->
  
  

Environment

vSphere 7.x
vSphere 8.x

Cause

This issue is attributed to a third-party software interaction. It typically occurs when the backup software improperly retains an active disk session or fails to release a proxy hot-add session locked against the parent virtual disk.

Resolution

Restart the third-party backup server or the specific associated backup services to force the release of the locked file sessions.