If a datastore was accidentally deleted but the partition might still be present, you can attempt to re-mount it via the ESXi command line:
This feature introduces a mechanism. Instead of restoring data immediately, the system presents the backup files as a live NFS or iSCSI target, allowing the ESXi host to mount the backup instantly as a read-write datastore. recovering vmfs datastore
VMFS (Virtual Machine File System) is the clustered file system used by VMware vSphere. A datastore can become inaccessible due to: If a datastore was accidentally deleted but the
Symptoms: Datastore shows as "Unmounted" or "Corrupt," VMs missing, but LUN size correct. " VMs missing
Sudden power loss, host crashes (PSOD), or RAID controller failures can leave the volume header or resource bitmap inconsistent.