Introduction VMware Virtual Machine File System (VMFS) is the backbone of vSphere environments, designed for high-performance concurrent access by multiple ESXi hosts. Despite its robustness, VMFS is not immune to corruption. Among the most dreaded scenarios for a storage administrator is the loss or corruption of VMFS metadata—the critical set of structures that tells the hypervisor where files (virtual disks, configurations, snapshots) reside on the underlying LUN or disk device.
# List all partitions on a device (e.g., naa.6000...) partedUtil get /vmfs/devices/disks/naa.6000... fdisk -l /vmfs/devices/disks/naa.6000... Attempt to probe filesystem vmfs-fs-probe /vmfs/devices/disks/naa.6000...:1 View kernel VMFS errors tail -100 /var/log/vmkernel.log | grep -i vmfs recover vmfs metadata
dd if=/vmfs/devices/disks/naa.6000... bs=512 count=1 | hexdump -C Look for “VMFS” ASCII signature at offset 0x200. If present but higher-level structures corrupt, recovery is possible. Recovery options depend on whether you have backups, ESXi’s built-in repair utilities, or need third-party tools. 3.1 First Line: ESXi Built-in Commands A. vmfs-fs-rescue (VMFS3/5 only – deprecated in newer versions) For older environments, this utility attempts to rebuild the FDC table from residual metadata. Introduction VMware Virtual Machine File System (VMFS) is
Without valid metadata, a datastore appears as a raw partition, empty, or reports the dreaded "Not a VMFS datastore" error. However, the actual virtual machine data (VMDK files, memory state, logs) often remains physically present on the disk. Recovering the metadata is therefore less about file “undelete” and more about reconstructing the logical map that points to existing data blocks. # List all partitions on a device (e
vmfs-fs-rescue /vmfs/devices/disks/naa.6000...:1 This creates a lost+found directory with recoverable files. It does not preserve original folder structure but may recover VMDK and VMX files. VMFS does not have an fsck like ext4. Instead, VMware relies on journal replay on mount. To force replay:
Expected output from vmfs-fs-probe if metadata intact: