The entire disk space is reserved and unavailable for use by other VMs. Before writing to a new block, a zero has to be written, increasing the input/output operation per second ( IOPS) on new blocks compared to eager disks. This space may contain stale data on the physical media. Thick or lazy zeroed thick VMDK: A thick disk has all space allocated at creation time.Such disks may take a long time during creation compared to other disk formats.
The type of virtual disks are mainly the same since vSphere 4.0: There are different types of virtual disks depending on the provisioning method, pre- allocated or dynamic. But note that USB datastores are just unsupported by VMware. VMware vSphere supports different types of storage architectures, both internally (in this case the controller is crucial, that must be in the HCL) or externally with shared SAS DAS, SAN FC, SAN iSCSI, SAN FCoE, or NFS NAS (in those case the HCL is fundamental for the external storage, the fabric elements, and the host adapters).įor local storage, with vSphere 6.x it's possible to use USB disks, not only as boot disks, but also to run VMs.
