Recover Vmfs Metadata Portable Here

# Unmount if mounted vmkfstools -V /vmfs/devices/disks/naa.6000...:1 # Remount to replay journal esxcfg-volume -M <datastore_name> If corruption is due to ESXi detecting a duplicate UUID, resignaturing preserves metadata but changes datastore identity:

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. recover vmfs metadata

# Find backup superblock locations (example for VMFS6) # Primary at LBA 1, backup at LBA 2048, 4096, etc. dd if=/vmfs/devices/disks/naa.6000... of=/tmp/backup_superblock bs=512 count=1 skip=2048 # Restore primary dd if=/tmp/backup_superblock of=/vmfs/devices/disks/naa.6000... bs=512 count=1 seek=1 Incorrect offsets can destroy data. Only attempt if you have exact documentation for your VMFS version. 3.3 Third-Party Recovery Tools (Recommended for Critical Data) Several commercial tools specialize in VMFS metadata reconstruction. They work by scanning the raw device for file signatures and rebuilding the allocation map. # Unmount if mounted vmkfstools -V /vmfs/devices/disks/naa

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. Recovery options depend on whether you have backups,

VMFS version: 6.81 Volume UUID: 4a5b3c2d-... Number of heartbeats: 3 If it fails with No VMFS filesystem found , metadata is corrupt or missing. Use dd and hdparm to check if basic partition table is readable:

# 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