During Installation of ESX Server 3.0.2 or later the VMFS Partition Is Listed as Unknown on Partitioning Options Page
Details
During the installation of ESX Server 3.0.2 or later, you can select Recommended or Advanced partitioning on the Partitioning Options page. If you select Recommended and then click Next, a warning displays the existing partitions that are about to be removed. In the partition list, the Virtual Machine File System (VMFS) partition is displayed as Unknown.
Solution
It is safe to accept the warning and proceed with the installation. The VMFS partition is displayed as Unknown due to an error in the underlying partitioning program. The re-partitioning operation is not affected by this error. As long as Preserve VMFS partitions is selected, VMFS partitions will not be destroyed. If you want to see the existing partition map, select Advanced on the Partitioning Options page. After you have viewed the existing partition map, you can return to the Partitioning Options page, and select Recommended.
