Which feature requires an administrator to configure an RDM with Virtual Compatibility Mode?
A. vMotion
B. Virtual Machine Snapshots
C. High Availability
D. N-port ID Virtualization
Correct Answer: B
Explanation/Reference:
Explanation:
Certain considerations and limitations exist when you use RDMs.
The RDM is not available for direct-attached block devices or certain RAID devices. The RDM uses a SCSI serial number to identify the mapped device.
Because block devices and some direct-attach RAID devices do not export serial numbers, they cannot be used with RDMs.
If you are using the RDM in physical compatibility mode, you cannot use a snapshot with the disk. Physical compatibility mode allows the virtual machine to manage its own, storage-based, snapshot or mirroring operations.
Virtual machine snapshots are available for RDMs with virtual compatibility mode.
You cannot map to a disk partition. RDMs require the mapped device to be a whole LUN.
If you use vMotion to migrate virtual machines with RDMs, make sure to maintain consistent LUN IDs for RDMs across all participating ESXi hosts.
Flash Read Cache does not support RDMs in physical compatibility. Virtual compatibility RDMs are supported with Flash Read Cache.
Incorrect Answers:
A: vMotion does not require an RDM with Virtual Compatibility Mode. With vMotion, the virtual machines are migrated between hosts; however, the virtual machine disks are not moved during a vMotion migration.
C: High Availability (HA) does not require an RDM with Virtual Compatibility Mode. With HA, a virtual machine is restarted on another host in the event of a failure of the original host; however, the virtual machine disks are not moved during an HA recovery.
D: N-port ID Virtualization is a standard for mapping several worldwide port names to a single Fibre Channel HBA on a host. It does not require an RDM with Virtual Compatibility Mode.
References:
http://pubs.vmware.com/vsphere-55/index.jsp#com.vmware.vsphere.storage.doc/GUID-0114693D-94BF-4D0E-9BA4-416D4A51A5A1.html
Explanation/Reference:
Explanation:
Certain considerations and limitations exist when you use RDMs.
The RDM is not available for direct-attached block devices or certain RAID devices. The RDM uses a SCSI serial number to identify the mapped device.
Because block devices and some direct-attach RAID devices do not export serial numbers, they cannot be used with RDMs.
If you are using the RDM in physical compatibility mode, you cannot use a snapshot with the disk. Physical compatibility mode allows the virtual machine to manage its own, storage-based, snapshot or mirroring operations.
Virtual machine snapshots are available for RDMs with virtual compatibility mode.
You cannot map to a disk partition. RDMs require the mapped device to be a whole LUN.
If you use vMotion to migrate virtual machines with RDMs, make sure to maintain consistent LUN IDs for RDMs across all participating ESXi hosts.
Flash Read Cache does not support RDMs in physical compatibility. Virtual compatibility RDMs are supported with Flash Read Cache.
Incorrect Answers:
A: vMotion does not require an RDM with Virtual Compatibility Mode. With vMotion, the virtual machines are migrated between hosts; however, the virtual machine disks are not moved during a vMotion migration.
C: High Availability (HA) does not require an RDM with Virtual Compatibility Mode. With HA, a virtual machine is restarted on another host in the event of a failure of the original host; however, the virtual machine disks are not moved during an HA recovery.
D: N-port ID Virtualization is a standard for mapping several worldwide port names to a single Fibre Channel HBA on a host. It does not require an RDM with Virtual Compatibility Mode.
References:
http://pubs.vmware.com/vsphere-55/index.jsp#com.vmware.vsphere.storage.doc/GUID-0114693D-94BF-4D0E-9BA4-416D4A51A5A1.html