An administrator determines that when a host residing in a High Availability (HA) cluster fails, the virtual machines fail to restart on a remaining host, or will only restart after a long delay.
Which two conditions would account for this behavior? (Choose two.)
A. The virtual machines were not protected by vSphere HA at the time the failure occurred.
B. Distributed Resource Scheduler was not enabled at the time the failure occurred.
C. There is insufficient spare capacity on hosts with which the virtual machines are compatible.
D. The virtual machines contain physical Raw Device Mappings.
Correct Answer: AC
Explanation/Reference:
Explanation:
A: When implementing vSphere HA the master host in a cluster is responsible for monitoring the state of the slave hosts. If a slave host fails or becomes unreachable, the master host must identify which virtual machines need to be restarted. Thus if a virtual machine cannot restart on another host in the cluster when the host where it resides on happen to fail then it can be assumed that the master host did not protect the virtual machines at the time of the failure.
C: Being in a HA cluster does not necessarily mean that the workload is balanced. It could be that the remaining hosts that the virtual machines are supposed to use to restart do not have enough spare capacity to restart the virtual machines that was hosted on the failed host.
Incorrect Answers:
B: DRS will attempt to place a virtual machine on the host that is best suited to run that virtual machine at that specific time. A sort of intelligent placement when it is enabled. This means that DRS is more concerned with the balancing of resources in the cluster without downtime involved; and not the restart of virtual machines as is the case here.
D: Raw Device Mapping actually support vSphere HA and vMotion in that it is used to present a storage device directly to a virtual machine instead of encapsulating the disk into a file on a VMFS datastore; and will thus not be responsible for virtual machines not restarting on a host in a HA cluster.
References:
Kajamoideen M.R., VMWare ESXi Cookbook, Packt Publishing, Birmingham, 2014, p. 165
Lowe, S. & Marshall, N., Mastering VMWare vSphere 5.5, Wiley and Sons, Indianapolis, 2014, pp. 386, 644