If ESXi's built-in tools are unable to recover the datastore, consider using third-party tools, such as:

# Check filesystem (no repair) voma -m vmfs -f check -d /dev/disks/naa.600xxxx:1

# Identify the snapshot LUN esxcfg-volume -l

: A datastore is removed from the vSphere inventory or its underlying LUN is unmapped.

Once the datastore is recovered, re-register it with the ESXi host using the esxcli command: