vsphere-esxi-vcenter-server-55-storage-guide

vSphere StorageTable 17‐1. Features Available with Virtual Disks and Raw Device Mappings (Continued)ESXi Features Virtual Disk File Virtual Mode RDM Physical Mode RDMSnapshots Yes Yes NoDistributed Locking Yes Yes YesClustering Cluster-in-a-box only Cluster-in-a-boxcluster-across-boxesPhysical-to-virtual clusteringcluster-across-boxesSCSI Target-Based Software No No YesVMware recommends that you use virtual disk files for the cluster-in-a-box type of clustering. If you plan toreconfigure your cluster-in-a-box clusters as cluster-across-boxes clusters, use virtual mode RDMs for thecluster-in-a-box clusters.Create Virtual Machines with RDMs in the vSphere Web ClientWhen you give your virtual machine direct access to a raw SAN LUN, you create an RDM disk that resideson a VMFS datastore and points to the LUN. You can create the RDM as an initial disk for a new virtualmachine or add it to an existing virtual machine. When creating the RDM, you specify the LUN to bemapped and the datastore on which to put the RDM.Although the RDM disk file has the same.vmdk extension as a regular virtual disk file, the RDM containsonly mapping information. The actual virtual disk data is stored directly on the LUN.This procedure assumes that you are creating a new virtual machine. For information, see the vSphere VirtualMachine Administration documentation.Procedure1 Right-click any inventory object that is a valid parent object of a virtual machine, such as a datacenter,folder, cluster, resource pool, or host, and select New Virtual Machine.2 Select Create a new virtual machine and click Next.3 Follow the steps required to create a virtual machine.4 On the Customize Hardware page, click the Virtual Hardware tab.5 (Optional) To delete the default virtual hard disk that the system created for your virtual machine,move your cursor over the disk and click the Remove icon.6 From the New drop-down menu at the bottom of the page, select RDM Disk and click Add.7 From the list of SAN devices or LUNs, select a raw LUN for your virtual machine to access directly andclick OK.The system creates an RDM disk that maps your virtual machine to the target LUN. The RDM disk isshown on the list of virtual devices as a new hard disk.8 Click the New Hard Disk triangle to expand the properties for the RDM disk.9 Select a location for the RDM disk.You can place the RDM on the same datastore where your virtual machine configuration files reside, orselect a different datastore.NOTE To use vMotion for virtual machines with enabled NPIV, make sure that the RDM files and thevirtual machine files are located on the same datastore. You cannot perform Storage vMotion whenNPIV is enabled.160 VMware, Inc.