If metadata is intact but datastore is unmounted:
When a VMware VMFS (Virtual Machine File System) datastore becomes inaccessible, it can be due to various reasons, including but not limited to: vmware vmfs datastore inaccessible
| Cause Category | Specific Examples | |----------------|-------------------| | | Fibre Channel (FC) zone changes, iSCSI session timeouts, misconfigured multipathing (Round Robin, Fixed, MRU) | | LUN trespass/ownership | Active-active or active-passive arrays; ALUA misconfiguration; controller failover without proper SCSI-3 reservations | | VMFS metadata corruption | Abrupt power loss during metadata flush, inconsistent heartbeat regions, corrupt file descriptor blocks | | Snapshot/LUN exhaustion | Datastore filled to 100% capacity preventing write operations | | Storage array maintenance | LUN masking changes, volume deletion, firmware upgrades without host coordination | | vSphere locking issues | Stale SCSI reservations, orphaned locks from ESXi hosts that no longer exist | If metadata is intact but datastore is unmounted:
To troubleshoot an inaccessible VMFS datastore, follow these steps: iSCSI session timeouts