A virtual machine is using a Fibre Channel attached Raw Device Mapped (RDM) LUN.
Which of the following applications used with the virtual machine would require the
RDM to be in Physical Compatibility Mode (Choose Three)?
A.
Physical Server to Virtual Machine Clustering
B.
SAN Management Agents
C.
Storage Array based Replication
D.
SCSI-target based software
E.
VMware Snapshots
Explanation:
Setup for Failover Clustering and Microsoft Cluster Service ESX 4.0 ESXi 4.0 vCenter
Server 4.0, page 25.
Cluster Physical and Virtual Machines
A standby host cluster has specific hardware and software requirements.
Use RDMs in physical compatibility mode (pass-through RDM). You cannot use virtual
disks or RDMs in virtual compatibility mode (non-pass-through RDM) for shared
storage. [A is correct].
Physical compatibility mode allows the guest operating system to access the hardware
directly. Physical compatibility is useful if you are using SAN-aware applications in the
virtual machine. However, a virtual machine with the physical compatibility RDM
cannot be cloned, made into a template, or migrated if the migration involves copying the
disk.
Virtual compatibility allows the RDM to behave as if it were a virtual disk, so you can
use such features as snapshotting, cloning, and so on. [Therefore E is incorrect].
Recommended Detailed Material on RDM’s
Physical mode for the RDM specifies minimal SCSI virtualization of the mapped device,
allowing the greatest flexibility for SAN management software. In physical mode, the
VMkernel passes all SCSI commands to the device, with one exception: the REPORT
LUNs command is virtualized, so that the VMkernel can isolate the LUN for the owning
virtual machine. Otherwise, all physical characteristics of the underlying hardware are
exposed. Physical mode is useful to run SAN management agents [B above] or other
SCSI target based software [D above] in the virtual machine.
Part 2: Configure iSCSI SAN Storage (13 questions)