The virtual disk attach operation to the virtual machine fails with "Provided backing file is not accessible from host."

Products

• VMware vSphere ESXi 8.0
• VMware vCenter Server 8.0

Issue/Introduction

The virtual disk attach operation to the virtual machine fails with the following error :

Invalid configuration for device '0'.
Device: VirtualDisk.
Provided backing file is not accessible from host.

Environment

vCenter Server 8.0
ESXi 8.0

Cause

This issue may occur if there is an abnormality in the datastore where the target virtual disk for the attach operation is located.

Resolution

This error occurs when the ESXi host is unable to access the storage device where the virtual disk is located. Please refer to the following steps to perform recovery and troubleshooting.

1. Rescan Storage Adapters

Update the connectivity status between the ESXi host and the storage.

• For block storage (FC/iSCSI, etc.) :
  In the vSphere Client, select the host and navigate to [Configure] > [Storage] > [Storage Adapters], then click [RESCAN STORAGE].
  
  
• For NFS datastores :
  Check if the target datastore is in an "Unmounted" state and perform a remount operation if necessary.

2. Verify Communication Paths

If connectivity is not restored after a rescan, verify the communication path from the host to the storage.

• Confirm network connectivity from the host to the storage device (target/server).
  
  
• For NFS datastores, ensure that communication is not being blocked by the host's firewall rules or any network path along the way.

3. Contact Hardware Vendor for Investigation

If the device remains unrecognized or inactive after following the steps above, a physical failure of the storage device or an issue within the connection path is suspected.
Consider requesting a hardware inspection from your storage device manufacturer.

Additional Information

Japanese version of this KB : https://knowledge.broadcom.com/external/article/430855