Which two statements are true about Unplanned Device Loss in a vSphere 5 environment? (Choose two.)
A.
It is a condition where an ESXi host determines a device loss has occurred that was not planned.
B.
Performing a storage rescan restores access to the device.
C.
It is a condition where an ESXi host is unable to determine why device loss occurred.
D.
Performing a storage rescan removes the persistent information related to the device.
http://pubs.vmware.com/vsphere-50/index.jsp?topic=%2Fcom.vmware.vsphere.storage.doc_50%2FGUID-BA39DB47-F8DB-4945-B061-1B6FF3DD12E1.html
Unplanned device loss is a condition that occurs when your ESXi host permanently loses connection to a storage device.
Typically, unplanned device loss is unintentional and can occur when a storage device is unmapped, removed, or its unique ID changes, or when there is an unrecoverable hardware error.
If you experience an unplanned device loss condition, you must unmount any related datastores and perform a storage rescan to remove the persistent information associated with the device.
vsphere-esxi-vcenter-server-50-storage-guide, p.p 132
“Although the ESXi host cannot determine the reason for a device loss, the host supports the loss detection.” = C
“If you experience an unplanned device loss condition, you must unmount any related datastores and perform
a storage rescan to remove the persistent information associated with the device.” = D