VMFS Datastore Inaccessible After Being Overwritten as an ESXi Boot Device
Article ID: 447384
Updated On:
Products
Issue/Introduction
A VMFS datastore becomes completely inaccessible or shows as unformatted/corrupted following an ESXi host installation or deployment. Some VMs on host have lost their disks, have no console access, and cannot be powered off. This occurs because the target storage LUN containing active virtual machine workloads was incorrectly designated as the destination for the ESXi boot image, resulting in partition table degradation and partial metadata overwrite.
Environment
VMware vSphere ESXi 8.0
VMware vCenter Server 8.0
Cause
The VMFS datastore partition table and metadata blocks were overwritten when the storage LUN was selected as the installation target for an ESXi boot device configuration.
Resolution
Once the datastore has been overwritten you can use the following steps to restore the data
- Quarantine the Storage LUN: Immediately place the affected ESXi host into maintenance mode or unpresent the LUN from the host to prevent further background disk writes, logging operations, or dump file generation from further corrupting remaining blocks.
- Review Storage-Array Snapshots: Coordinate with your storage administration team to identify and restore from an array-level snapshot or replication copy taken prior to the installation event.
- Analyze Partition Metadata: If no storage backups exist, engage an enterprise data recovery service or utilize storage utility tools to assess if the underlying VMFS volume descriptors can be manually reconstructed, keeping in mind that sectors physically written to by the new ESXi system installation are unrecoverable.
If data is no longer needed or has already been restored then either reformat or delete the LUN.
Additional Information
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