6.7

5 Select a compatibility mode.
Option Description
Physical Allows the guest operating system to access the hardware directly. Physical
compatibility is useful if you are using SAN-aware applications on the virtual
machine. However, a virtual machine with a physical compatibility RDM cannot be
cloned, made into a template, or migrated if the migration involves copying the
disk.
Virtual Allows the RDM to behave as if it were a virtual disk, so that you can use such
features as taking snapshots, cloning, and so on. When you clone the disk or
make a template out of it, the contents of the LUN are copied into a .vmdk virtual
disk file. When you migrate a virtual compatibility mode RDM, you can migrate the
mapping file or copy the contents of the LUN into a virtual disk.
6 Accept the default or select a different virtual device node.
In most cases, you can accept the default device node. For a hard disk, a nondefault device node is
useful to control the boot order or to have different SCSI controller types. For example, you might
want to boot from an LSI Logic controller and share a data disk with another virtual machine using a
BusLogic controller with bus sharing turned on.
7 (Optional) If you selected virtual compatibility mode, select a disk mode to change the way that disks
are affected by snapshots.
Disk modes are not available for RDM disks using physical compatibility mode.
Option Description
Dependent Dependent disks are included in snapshots.
Independent - Persistent Disks in persistent mode behave like conventional disks on your physical
computer. All data written to a disk in persistent mode are written permanently to
the disk.
Independent - Nonpersistent Changes to disks in nonpersistent mode are discarded when you power off or
reset the virtual machine. With nonpersistent mode, you can restart the virtual
machine with a virtual disk in the same state every time. Changes to the disk are
written to and read from a redo log file that is deleted when you power off or reset.
8 Click OK.
SCSI and SATA Storage Controller Conditions,
Limitations, and Compatibility
To access virtual disks, CD/DVD-ROM, and SCSI devices, a virtual machine uses storage controllers,
which are added by default when you create the virtual machine. You can add additional controllers or
change the controller type after virtual machine creation. You can make these changes while you are in
the creation wizard. If you know about node behavior, controller limitations, and compatibility of different
types of controllers before you change or add a controller, you can avoid potential boot problems.
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