While building a new vSphere cluster, a systems administrator needs to format a 15 TB iSCSI LUN so that six ESXi hosts can read and write to it at the same time, power on virtual machines, and use vMotion without corrupting data. The file system must provide distributed on-disk locking that allows concurrent access from all hosts. Which file system type should the administrator choose when formatting the LUN?
VMFS is VMware's clustered file system. It was designed for shared storage in vSphere and lets many ESXi hosts mount the same datastore concurrently while a built-in distributed locking mechanism protects virtual-machine files from simultaneous writes. Standard ext4 lacks any cluster lock manager, so mounting it read-write on more than one host risks immediate corruption. NTFS relies on a single-owner (shared-nothing) model in Windows clusters and is not supported by ESXi; it cannot be mounted read-write by multiple hypervisors at the same time. ReFS is Windows-only; when placed in a Cluster Shared Volume it redirects updates through one coordinator node rather than allowing true simultaneous block-level writes, and it is also unsupported by ESXi. Therefore, VMFS is the only option that satisfies the requirement for safe, concurrent multi-host access.