VMware Backup Fails Because Virtual Machine Disks Need Consolidation

If virtual machine disks need consolidation, backups fail until you clear locks on virtual machine disks or on the access node (VSA proxy) where disks are attached.

Symptoms

A backup of a VMware virtual machine fails with the following error code:

Error Code: [91:399]

Description: The virtual machine [vm_name] reports that it has virtual disks that need consolidation and this could not be performed automatically. In order to prevent a further buildup of delta disks and possible stability issues with the virtual machine, further backups of this virtual machine will not be performed until this condition is corrected. Please check if there are any locks on the virtual disks or if the disks are still attached to a backup proxy. [Unable to access file since it is locked Virtual disk file [[datastore_name] vm_name_folder/disk_name.vmdk] is attached to virtual machine [vm_name]]

Causes

To prevent a buildup of delta disks and to avoid possible stability issues, backups are disabled for a virtual machine that requires disk consolidation.

Resolution

Clear the locks for the disks identified in the JPR. The disks could be locked on the source VM or on the access node (VSA proxy) where the disks are attached for the backup.

Steps to try:

• Verify the disk is not still mounted via HotAdd to the VSA Access Node by checking for any extra disks when editing the Virtual Machine hardware. If necessary, remove the disk from the Access Node by editing the virtual machine in vCenter and removing auxiliary attached disks.
• Locate the VM in question and try to manually run 'Consolidate Disks' from vSphere.
• Perform a Storage vMotion to another Datastore, which automatically attempts to consolidates disks as part of the moment process. This is often helpful if a manual 'Consolidate Disks' task does not function.