6.0.1

Table Of Contents
Snapshots
Makes it possible to use virtual machine snapshots on a mapped volume.
Snapshots are not available when the RDM is used in physical compatibility
mode.
vMotion
Lets you migrate a virtual machine with vMotion. The mapping le acts as a
proxy to allow vCenter Server to migrate the virtual machine by using the
same mechanism that exists for migrating virtual disk les.
Figure 182. vMotion of a Virtual Machine Using Raw Device Mapping
VMFS volume
mapping file
address
resolution
mapped device
Host 2Host 1
VM2VM1
VMotion
SAN Management
Agents
Makes it possible to run some SAN management agents inside a virtual
machine. Similarly, any software that needs to access a device by using
hardware-specic SCSI commands can be run in a virtual machine. This kind
of software is called SCSI target-based software. When you use SAN
management agents, select a physical compatibility mode for the RDM.
N-Port ID Virtualization
(NPIV)
Makes it possible to use the NPIV technology that allows a single Fibre
Channel HBA port to register with the Fibre Channel fabric using several
worldwide port names (WWPNs). This ability makes the HBA port appear as
multiple virtual ports, each having its own ID and virtual port name. Virtual
machines can then claim each of these virtual ports and use them for all
RDM trac.
N You can use NPIV only for virtual machines with RDM disks.
VMware works with vendors of storage management software to ensure that their software functions
correctly in environments that include ESXi. Some applications of this kind are:
n
SAN management software
n
Storage resource management (SRM) software
n
Snapshot software
Chapter 18 Raw Device Mapping
VMware, Inc. 207