The underlying hardware was fine. A routine firmware update on the SAN had crashed midway, corrupting the partition table on the LUN. The disks were still there, spinning away, but ESXi couldn’t see the VMFS signature anymore. To the hypervisor, the partition now looked like raw, unformatted space.
Her boss, half-asleep, yelled from the kitchen: “Can you just restore from backup?” vmware repair vmfs partition
“Repaired the VMFS partition,” she said, trying not to smile too wide. The underlying hardware was fine
Next, she used vmfs-fdisk —a hidden gem in ESXi’s recovery toolkit—to scan for VMFS signatures: To the hypervisor, the partition now looked like
She SSH’d into one of the ESXi hosts and ran the first command she’d scribbled in her notebook years ago, during a VMware troubleshooting course she almost fell asleep in:
She was the senior virtualization engineer for a mid-sized financial firm. Fifty-seven virtual machines—including the exchange server, the CRM, and the entire payroll system—lived on a single 12 TB VMFS datastore. And now, that datastore had vanished from vCenter.