Section 8 – Perform Basic Troubleshooting and Alarm Management
- Objective 8.5 – Perform Basic Troubleshooting for HA/DRS and VMotion
Which of the following are requirements for successful VMotion migration (Choose Two)?
A.Gigabit Ethernet networking must exist between the source and destination hosts
B.Virtual Machines must have access to the same subnets on the source and destination hosts
C.CPUs with the same clock speed and cache size must exist on both the source and destination hosts
D.Virtual Machines cannot be configured to use RDMs
vSphere Resource Management Guide ESX 4.0 ESXi 4.0 vCenter Server 4.0Page 48.
To enable the use of DRS migration recommendations, the hosts in your cluster must be part of a VMotion
network.If the hosts are not in the VMotion network, DRS can still make initial placement recommendations.
To be configured for VMotion, each host in the cluster must meet the following requirements:
The virtual machine configuration file for ESX/ESXi hosts must reside on a VMware Virtual Machine File System (VMFS).
VMotion does not support raw disks or migration of applications clustered using Microsoft Cluster Service (MSCS).
VMotion requires a private Gigabit Ethernet migration network between all of the VMotion enabled managed hosts. [A above].
Whilst it may not be an absolute requirement that virtual machines must have access to the same subnets on the source and destination hosts for VMotion to occur, if virtual machines do not have this access, then they can no longer communicate, thus rendering a VMotion migration un successful. [B is correct].
VMotion compatibility means that the processors of the destination host must be able to resume execution using the equivalent instructions where the processors of the source host were suspended. Processor clock speeds and cache sizes might vary, but processors must come from the same vendor class (Intel versus AMD) and same processor family to be compatible for migration with VMotion. [C is incorrect].
VMotion and RDMs
You can VMotion a VM that uses RDM as long as the RDM is configured in virtual compatibility mode. [D is incorrect].
An administrator is configuring a VMware HA Cluster for three hosts and their resident VMs. The HA cluster will be configured to support a single host failure and resource reservations must be enforced during a failover event. Assuming default settings, how does HA determine the failover capacity determined?
A.Using the highest CPU Reservation and the Available Memory values for any given virtual machine in the cluster
B.Using the highest CPU Reservation and Memory Reservation values of any given virtual machine in the cluster
C.Using an average of the total CPU Reservation and Available Memory values of all virtual machines In the cluster
D.Using an average of the total CPU Reservation and Memory Reservation values of all virtual machines in the cluster
DRS on a cluster with two ESX Hosts is set to Fully Automated mode. One server in the cluster is running at 98% CPU utilization, while the other host is running at 52% utilization.
Upon analysis, it appears that none of the virtual machines (VMs) are being migrated to the other server, and no recommendations are being generated. Which of the following are the most likely causes of the problem (Choose Two)?
A.The ESX Server has CPU features that are incompatible with other hosts in the cluster
B.The VMotion licenses for the cluster have expired
C.The current DRS Migration Threshold setting is too conservative
D.Insufficient resources exist to perform the VMotion migration
When migrating a machine with VMotion, what is the difference between High Priority and Low Priority (Choose Two)?
A.High priority reserves resources on the host and destination. High priority migrations always succeed.
B.High priority reserves resources on the host and destination. High priority migrations will not proceed if the resources are unavailable.
C.Low priority does not reserve resources on the host and destination. Low priority migrations always succeed.
D.Low priority does not reserve resources on the host and destination. Low priority migrations will not proceed if the resources are unavailable.
What function does VMware Enhanced VMotion Compatibility provide?
A.The ability to VMotion virtual machines between Intel and AMD processors
B.The ability to VMotion virtual machines between CPUs with hardware virtualization and CPUs Without this support
C.The ability to VMotion virtual machines between CPUs with a common supported baseline
D.The ability to VMotion virtual machines between ESX Hosts with different core counts
VMware VMotion and CPU Compatibility
VMware Enhanced VMotion Compatibility (EVC) facilitates VMotion between different CPU generations. When enabled for a cluster, EVC ensures that all CPUs within the cluster are VMotion compatible.
Assuming the appropriate HA configuration options have been selected, which of the following situations would result in VMware HA restarting virtual machines (Choose Two)?
A.A guest OS is manually powered off
B.A guest OS fails
C.An ESX Server in the cluster becomes isolated from the network
D.An ESX Server in the cluster is put into Maintenance Mode
vSphere Availability Guide ESX 4.0 ESXi 4.0 vCenter Server 4.0, page 11, 12, 23.
VMware HA provides high availability for virtual machines by pooling them and the hosts they reside on into a cluster. Hosts in the cluster are monitored and in the event of a failure, the virtual machines on a failed host are restarted on alternate hosts.
If you select Enable VM Monitoring, the VM Monitoring service (using VMware Tools) evaluates whether each virtual machine in the cluster is running by checking for regular heartbeats from the VMware Tools process running inside the guest. If no heartbeats are received, this is most likely because the guest operating system has failed or VMware
Tools is not being allocated any time to complete tasks. In such a case, the VM Monitoring service determines that the virtual machine has failed and the virtual machine is rebooted to restore service. [B above]
Host network isolation occurs when a host is still running, but it can no longer communicate with other hosts in the cluster. With default settings, if a host stops receiving heartbeats from all other hosts in the cluster for more than 12 seconds, it attempts to ping its isolation addresses. If this also fails, the host declares itself as isolated from the network. When the isolated host’s network connection is not restored
for 15 seconds or longer, the other hosts in the cluster treat it as failed and attempt to fail over its virtual machines. [C above]
In a cluster using DRS and VMware HA with admission control turned on, virtual machines might not be evacuated from hosts entering maintenance mode. This is because of the resources reserved to maintain the failover level. You must manually migrate the virtual machines off of the hosts using VMotion.
vCenter Server is running within a virtual machine (VM) that is part of a VMware HA and DRS cluster. The vCenter Server VM can migrate between all hosts in the cluster by using VMotion. DRS is configured for partial automation.
What happens if the ESX host that is currently running the vCenter Server VM experiences a power outage?
A.This situation cannot occur because vCenter Server cannot be installed on a VMware HA cluster
B.vCenter Server will remain offline, but all virtual machines on the remaining hosts will continue without interruption
C.VMware HA will restart the vCenter Server VM on another host
D.All DRS cluster operations will be unavailable until the failed ESX Host is brought back online
In Guided Consolidation, a higher Confidence Metric indicates which of the following?
A.The source machine is a better candidate for virtualization
B.The data collected from the source machine is more reliable
C.A given destination ESX Server is a better fit for the source machine
D.The displayed destination ESX Server is the best fit from all available ESX Servers
vSphere Basic System Administration vCenter Server 4.0 ESX 4.0 ESXi 4.0, page 95.
About the Confidence Metric
One important metric displayed in the Analysis tab is the Confidence metric. During the analysis phase, performance data about each selected system is collected. This data is used to find a host with resources that match the collected data to determine a recommendation for each candidate.
The recommendation indicates how well suited, based on the collected data, a candidate is to a particular virtual machine host system. Confidence refers to the reliability of the recommendation and it is a function of the duration of the analysis. Recommendations based on longer periods of analysis – and therefore more performance data – receive a higher level of confidence.
An ESX Server in a DRS cluster is placed into Maintenance Mode. Which of the following conditions are true (Choose Two)?
A.If the DRS cluster is in fully automated mode, DRS will make a migration
recommendation and then VMotion Virtual Machines to other ESX servers
B.If the DRS cluster is in partially automated mode then the Virtual Machines that have
a High Restart Priority will be moved to another ESX Server
C.If the DRS cluster is in partially automated mode then the vCenter Administrator must
VMotion Virtual Machines to another ESX Server
D.If the DRS cluster is in fully automated mode, DRS will automatically VMotion
Virtual Machines to other ESX Servers
Which of the following can be configured or modified from the Resource Allocation tab of a DRS Cluster (Choose Two)?
A.virtual machine CPU share value
B.expandable reservation for resource pools in the cluster
C.virtual machine memory reservation
D.share priority for resource pools in the cluster
The screenshot shows modification of the virtual machine CPU share value