vmfs2recover -d /dev/sdb -o 128 -b 1048576 --force VMFS uses heartbeat regions to manage cluster integrity. A stale heartbeat prevents mounting.
esxcli storage core device set -d naa.xxx -r 0 vmkfstools --clearheartbeat /vmfs/devices/disks/naa.xxx:1 When the FDT is lost, files become inaccessible even if data blocks remain intact. vmfs recover
– bundled with vSphere CLI: