To deploy Microsoft Cluster on VMware ESX 4.1 is not new thing, you may need to choose the right storage protocol in this case. According to VMware best practices, on Fiber Channel SAN will be supported with the current version. You will need to present the Share Storage via FC LUN to build the microsoft cluster in VMware environment. ISCSI & NFS both are not supported in this case.

You can view the Official VMware Documentation from here.