Error: "Unknown error" when consolidating snapshots with the NFS NetApp NAS plugin

Products

• VMware vSphere ESXi

Issue/Introduction

• When the NetApp NAS plugin is in use, users may not be able to consolidate powered-on snapshots. The consolidation fails with "An error occurred while consolidating disks: Unknown error."

 

• In ESXi var/run/log/hostd.log, you see the following entries:

YYYY-MM-DDTHH:MM:SS. Er(##) Hostd[########]: [Originator@#### sub=Vmsvc.vm:/vmfs/volumes/Datastore/<VM Name>/<VM Name>.vmx] Exception Insufficient permission to access file trying to get sizes from /vmfs/volumes/Datastore/<VM Name>/<VM Name>.vmdk

• In ESXi /vmfs/volumes/Datastore/<VM Name>/vmware.log for the affected VM:, you see the below entries 

YYYY-MM-DDTHH:MM:SS Er(##) vmx - DISKLIB-LINK  : DiskLinkGetSize: Failed to get extent size: Insufficient permission to access file
YYYY-MM-DDTHH:MM:SS Er(##) vmx - ConsolidateFillSnapDiskTransferArray: Failed to fetch disk size of '/vmfs/volumes/Datastore/<VM Name>/<VM Name>-000001.vmdk' for consolidate: Insufficient permission to access file
YYYY-MM-DDTHH:MM:SS In(05) vmx  DISKLIB-VMFS  : "/vmfs/volumes/Datastore/<VM Name>/<VM Name>.vmx : open successful (5) size = ###########, hd = 0. Type 3
YYYY-MM-DDTHH:MM:SS In(05) vmx  DISKLIB-VMFS  : "/vmfs/volumes/Datastore/<VM Name>/<VM Name>.vmx : closed.
YYYY-MM-DDTHH:MM:SS Er(02) vmx  DISKLIB-LINK  : DiskLinkGetSize: Failed to get extent size: Unknown error
YYYY-MM-DDTHH:MM:SS Er(02) vmx  ConsolidateFillSnapDiskTransferArray: Failed to fetch disk size of 'vm:/vmfs/volumes/Datastore/<VM Name>/<VM Name>-000001.vmdk' for consolidate: Unknown error (5)
YYYY-MM-DDTHH:MM:SS In(05) vmx  ConsolidateStart: Failure while populating the snapDataPerCombineOperation array: 'Unknown error' (5)

Environment

• VMware vSphere 8.x
• VMware vSphere 7.x

Cause

The NetApp plugin does not have permission to lock the in-use VMDK. Consequently, the powered-on VM cannot be consolidated.

Resolution

Contact NetApp support to resolve this permanently.

Workaround:

Option 1: Power down the VM

1. Perform a graceful shutdown of the VM.

2. Consolidate the snapshots.

Option 2: Release plugin-level locks on a live VM (Host level)

1. Stop the VAAI NAS daemon by running the following command:

   • /etc/init.d/vaai-nasd stop

2. Perform the Snapshot Consolidation via the vSphere Client.
3. Restart the daemon by running the following command:
   
   • /etc/init.d/vaai-nasd start

 Note: Stopping the vaai-nasd service temporarily disables VAAI primitives, such as Hardware Accelerated Clone or Snapshot. This forces ESXi to use standard NFS client calls, which successfully bypasses the plugin’s locking mechanism and allows the vim.vm.Snapshot.consolidate task to complete.