Section 8 – Perform Basic Troubleshooting and Alarm Management
- Objective 8.7 – Create and Respond to vCenter Utilization Alarms
QUESTION 90
During peak operating hours, an Administrator finds that a business critical application is not performing as well as during normal hours. Which of the following memory management methods could be used to guarantee the application performs well at all times?
A.Set a Reservation equal to the Average Memory utilization of the virtual machine running the application
B.Set a Reservation equal to the Peak Memory utilization of the virtual machine running the application
C.Set the Share level to High for the virtual machine running the application
D.Set the Share level to High for the virtual machine running the application and set all other virtual machines to Low
Answer: B
Explanation:
Memory Provisioning Recommendations for VMware Infrastructure 3 Operational Best Practices page 8.
Memory Reservations, Limits, and Shares
Memory Reservations are an ESX Server memory management technique used to control how memory is allocated from an either an explicit or implicit resource pool by the VMkernel to a virtual machine or group of virtual machines.
Reservations consist of two settings – a reservation, or guaranteed amount of physical memory that will always be available to the virtual machine(s), and a limit, which is the absolute maximum physical memory a virtual machine or group of virtual machines can consume on the host
During peak operating hours, by definition more systems and more resources including memory, will be being consumed. Therefore memory reservation is required. By setting a reservation equal to the peak memory utilization, this will guarantee the application receives all memory it requires.
QUESTION 91
A user wants to receive an email notification when the virtual machine CPU usage enters a warning state, and again when the condition has been resolved. Which two state changes must be selected to receive the appropriate notifications (Choose Two)?
A.red-green state change
B.green-yellow state change
C.yellow-red state change
D.yellow-green state change
Answer: BD
Explanation:
vSphere Basic System Administration vCenter Server 4.0 ESX 4.0 ESXi 4.0, page 235.
VMware uses colors to denote alarm severity:
Normal – green
Warning – yellow
Alert – red
You can set alarms to trigger when the state changes from green to yellow, yellow to red, red to yellow, and yellow to green.
When the virtual machine CPU usage enters a warning state, it will change from Normal (green) to Warning (yellow). When the condition has been resolved it will change from Warning (yellow) to Normal (green).
QUESTION 92
A Windows virtual machine (VM) is experiencing poor application performance. The suspected issue is a lack of available memory. Windows Task Manager shows 30% of the memory within the VM is not currently being used. What does this indicate and what could be checked next?
A.The VM has memory available, however it may not actually have physical memory available. VMkernel swap activity on the ESX Server host should be checked next.
B.Windows Task Manager is not reading actual memory usage in the VM. Windows System Monitor should be used to get a precise reading on memory usage.
C.The application problems are definitely due to a non-memory related problem. CPU affinity settings should be checked for this VM.
D.The application problems are definitely due to a non-memory related problem. CPU utilization should be checked next using Windows Task Manager.
Answer: A
Explanation:
The poor application performance due to suspected lack of available memory suggests paging is the cause of the issue. If Windows Task Manager shows 30% of the memory within the VM is not currently being used, then paging must be occurring within the VM host. Therefore poor application performance should now be checked.
QUESTION 93
A group of ABC virtual machines has been deployed using thin disks due to limited storage space availability. The storage team has expressed concern about extensive use of this type of provisioning. Which of the following actions can be taken to inform an administrator when an unacceptably large number of virtual machines are being deployed using thin disk provisioning?
A.Modify the default Datastore Usage on Disk alarm with a determined percentage. Create a trigger For the alarm with an e-mail or SNMP notification option.
B.Use the default Host Storage Status alarm. Create a trigger for the alarm with an e-mail or SNMP notification option.
C.Create an alarm for Datastore Disk Overallocation and determine an appropriate percentage. Create A trigger for the alarm with an e-mail or SNMP notification option.
D.Create an alarm for Disk Usage and determine the appropriate amount. Create a trigger for the Alarm with an e-mail or SNMP notification option.
Answer: C
QUESTION 94
Several Virtual Machines residing in a resource pool are exhibiting poor performance, and a critical VM in the pool appears hung. The resource pool has been allocated exactly 500 MHz of CPU and does not have the Expandable Reservation option selected. The cluster in which the resource pool resides has a total of 6000 MHz, with 1000 MHz available. Which step can be used to increase the performance of the critical VM?
A.increase the CPU Reservations on the resource pool
B.increase the CPU Limit on the resource pool
C.increase the CPU Limit on the critical VM
D.increase the CPU Reservations on the critical VM
Answer: B
QUESTION 95
A Windows virtual machine (VM) viewed through Task Manager shows CPU utilization averaging 95-100%.What does this indicate?
A.The VM is utilizing most of the CPU resources allocated to it. The CPU Ready value should be checked to determine if this is a resource constraint.
B.The VM CPU reservation is not sufficient.
C.The VM has an impending performance problem. The running processes in Windows Task Manager should be checked to determine what applications are consuming CPU resources.
D.The VM has CPU affinity set to CPU 0 and is competing with the service console for CPU resources. esxtop should be run to confirm the diagnosis.
Answer: A
QUESTION 96
A user’s permission set is modified so that they can no longer create alarms. What will happen to the alarms already created by this user?
A.Alarms will be triggered if the event occurs.
B.Alarms will never be triggered.
C.Alarms will be triggered for critical state changes only.
D.Only ESX host alarms will be triggered.
Answer: A
QUESTION 97
It appears that a virtual machine (VM) is having performance problems because it does not have enough CPU resources available. Which of the following methods could be used to guarantee a VM gets 100% of a CPU on the host when it needs it? (Choose Two.)
A.set the CPU limit for this VM to 100%
B.set CPU affinity on that VM, pinning it to CPU 1 and set CPU affinity on all other VMs so that they specifically cannot use CPU 1
C.set CPU affinity on that virtual machine, pinning it to a CPU 1
D.set the CPU reservation for this VM to 100%
Answer: BD
Explanation:
vSphere Resource Management Guide, ESX 4.0, ESXi 4.0, vCenter Server 4.0, page 37,75.
Table 4-1. Resource Pool Attributes
Field – Reservation
Description – Guaranteed CPU or memory allocation for this resource pool. A nonzero reservation is subtracted from the unreserved resources of the parent (host or resource pool).
Setting the CPU reservation for this VM to 100% will prevent any other VM from accessing this CPU.
CPU Affinity – A virtual machine should use only the processors on a given node. By
Setting CPU affinity on that VM, pinning it to CPU 1 and setting CPU affinity on all other VMs so that they specifically cannot use CPU 1, will prevent any other VM from accessing this CPU.
QUESTION 98
What will most benefit a CPU-constrained VM?
A.the installation of a third-party management tool in the guest OS
B.the installation of the vmxnet virtual adapter
C.a decrease in the CPU-limit value
D.an increase in CPU shares
Answer: D
Explanation:
vSphere Basic System Administration vCenter Server 4.0 ESX 4.0 ESXi 4.0, page 155.
The values Low, Normal, High, and Custom are compared to the sum of all shares of all virtual machines on the server. If you increase CPU shares for this VM, it will gain proportionally more resources, improve performance and reduce CPU contention. Therefore D is correct.
QUESTION 99
A user wants to receive an email notification when the virtual machine CPU usage enters a critical state, and again when the problem has been resolved. Which two state changes must be chosen to receive the appropriate notifications? (Choose Two.)
A.green-yellow state change
B.yellow-red state change
C.red-green state change
D.yellow-green state change
Answer: BD
Explanation:
vSphere Basic System Administration vCenter Server 4.0 ESX 4.0 ESXi 4.0, page 235.
VMware uses colors to denote alarm severity:
Normal – green
Warning – yellow
Alert – red
You can set alarms to trigger when the state changes from green to yellow, yellow to red, red to yellow, and yellow to green.
When the virtual machine CPU usage enters a critical state, it will change from Warning (yellow) to Critical (red). When the condition has been resolved it will change from Warning (yellow) to Normal (green).
QUESTION 100
Which of the following are valid choices for optimizing performance of Virtual Machines? (Choose Three.)
A.Disable unused devices such as COM ports, Floppy drives, and CD ROM drive.
B.Avoid installing VMware tools on resource intensive virtual machines.
C.Defragment attached VMFS-3 volumes.
D.Tune and size virtual machine operating systems as you would on physical hosts.
E.Keep virtual machines that have similar resource requirements on the same host.
Answer: ADE
QUESTION 101
An administrator has deployed a new virtual machine on an ABC ESX Host, sc-vicuna04.vmeduc.com. Users are complaining of poor performance on the application running on the virtual machine. Performance tools display the results shown in the exhibit.
Which two tasks could you perform to try to improve the user experience (Choose Two)?
A.Remove the limit on the CPU settings of the virtual machine.
B.Add another vCPU to the virtual machine.
C.Migrate the virtual machine to another ESX host.
D.Remove CPU affinity on the Advanced CPU setting of the virtual machine.
Answer: AB
QUESTION 102
An administrator has received reports of poor network performance with a ABC virtual machine. Which of the following steps would improve the network performance of this virtual machine (VM)?
A.Adjust shares for the virtual NIC on the virtual machine
B.Add an additional uplink to the virtual switch this virtual machine is attached to
C.Traffic shape this virtual machine
D.Increase memory to the virtual machine
Answer: B
QUESTION 103
You have a dual-processor virtual machine (VM) that has affinity set so that the virtual CPUs are pinned to CPU 3 and 4 in VirtualCenter. The VM also has a reservation setting guaranteeing it 100% of available resources for those two CPUs. Performance is poor in this VM, however performance for all other VMs on this host is acceptable. What can you do to improve performance for this VM?
A.set CPU affinity on all other VMs prohibiting them from using CPU 3 and 4
B.remove the reservations on the CPUs in order to allow the VMkernel to switch the virtual CPUs between CPU 3 and 4 as needed
C.change the CPU share allocation from ‘Normal’ to ‘High’
D.change the CPU affinity settings to ensure that the virtual CPUs are running on two separate physical CPUs on the host
Answer: D
