Thin disk on ESX/ESXi server is based on file system, therefore when a backup is performed full disk is backed up.

It is possible to convert disk as thin after backup/restore process. When you configure a backup in the setup dialogue switch to "Files & Disks" tab and enable "After backup convert disk as thin" .

Please note:

- if target server is set to same host as VM thin disks are transferred directly as thin disk.

- if target server is an ESX/ESXi host thin disks are converted to thin after backup/restore process.

- if target server is not ESX/ESXi thin disks are backed up as full.

Incremental backup for licensed ESXi host (not the free edition), with at least Essential license, transfers and backups only used space and not full disk space. On the other hand incremental backup for ESXi free edition backups full disk space.

Please note:

- The disk must be located on a VMFS volume (backing does not matter).

- The virtual machine must have had no (zero) snapshots when changed block tracking was enabled "