As per VMware : When a virtual machine snapshot consolidation fails in vSphere, a Configuration Issue warning is reported in the Summary tab of a VM.
When you initiate snapshots deletion, virtual machine disks consolidation happens along with snapshot delete operation. But sometimes due to bad sectors or configuration file errors or due to backup tool, your virtual machines show a warning message “
Virtual Machine disks consolidation is needed”.
When you try to consolidate the disks it may fail to consolidate the disks and show error similar to the below:
Unable to access file since it is locked. An error occurred while consolidating disks: Failed to lock the file. Consolidation failed for disk node ‘scsix:x’: Failed to lock the file
Try to create a new snapshot and delete it to complete the disks consolidation. When you have this alert on a virtual machine, most of the cases, delete snapshots completes successfully without consolidating the disk and by creating another “ctk.vmdk” & “-0000xx.vmdk” files. If you create n-number of snapshots or your backup takes snapshots, those disks will be keep on creating new snapshot disk files without consolidating the older files, as shown below:
This error is due to backup vProxy VM, where the VM disks are part of the proxy VM and were not released after backup completion.
Right click the VM and select “Custom Attributes” to check the last backup attribute. There you can find the “Last backup details along with the vProxy server holding the disks which is not allowing to lock the files during consolidation.
Make a note of the vProxy server and go to that vProxy VM, select edit settings and identify the virtual disks assigned in vProxy VM from the affected VM (disk will be of the same VM path, grayed out) and delete it from the VM settings (do not select delete disk from storage), repeat the same step if there more than one disk from the VM associate to the vProxy server and click OK, now the vProxy has released the disk files, now go to the VM and try consolidate the disks, without any error, disks consolidation completes.
Please check the KB link to know how to consolidate.