Section 8 – Perform Basic Troubleshooting and Alarm Management
- Objective 8.8 – Monitor vSphere ESX/ESXi and Virtual Machine Performance
QUESTION 104
Users are complaining that a Windows application server Virtual Machine configured with 1GB RAM is not performing satisfactorily. An administrator opens the Performance Tab for the guest virtual machine and adds the counter for Memory Ballooned in MB. The Performance Chart displays a value of 240.
Which of the following actions should be taken?
A.Add more memory to the Virtual Machine.
B.Migrate the Virtual Machine to another host.
C.Monitor memory ballooning from the ESX host Performance Tab
D.Adjust the Mem.CtlMaxPercent to read 75.
Answer: B
Explanation:
Memory Provisioning Recommendations for VMware Infrastructure 3 Operational Best Practices, page 11.
Memory Balloon – This counter reflects the total amount of memory the VMkernel is effectively “borrowing” from virtual machines via the VMTools balloon driver running inside the guest OS. Balloon driver activity indicates over-commitment of ESX host memory. By default, the VMkernel may balloon up to 65% of a virtual machine’s configure RAM.
Users are complaining that a Windows application server is not performing satisfactorily.
The Memory Balloon counter indicates that memory is being borrowed by the Vmkernel from the virtual machine, indicating that the host has insufficient memory to service requirements from all virtual machines. Therefore either more memory should be added to the host or the guest should be moved to a system with more free memory.
QUESTION 105
The recommended maximum memory value displayed when configuring a VM represents?
A.The value that the OS vendor reports as being optimal for performance
B.The maximum value the guest OS supports
C.The threshold above which a host’s physical memory is insufficient to run the virtual machine at optimal performance
D.The threshold needed in order for the ESX Host to satisfy a reservation value
Answer: C
Explanation:
The virtual machine settings editor also shows a value for the maximum amount of memory for best performance. If you have only one virtual machine running on the host and you set virtual machine memory to this value, the virtual machine can run entirely in RAM. A virtual machine running completely in RAM performs better than a virtual machine that must swap some of its memory to disk.
QUESTION 106
When memory is reclaimed from a virtual machine using vmmemctl, what is the maximum amount that can be reclaimed by default?
A.50% of the unreserved memory
B.65% of the available memory
C.65% of the unreserved memory
D.50% of the available memory
Answer: C
Explanation:
Memory Provisioning Recommendations for VMware Infrastructure 3 Operational Best Practices, page 11.
Memory Balloon – This counter reflects the total amount of memory the VMkernel is effectively “borrowing” from virtual machines via the VMTools balloon driver running inside the guest OS. Balloon driver activity indicates over-commitment of ESX host memory. By default, the VMkernel may balloon up to 65% of a virtual machine’s configure RAM.
QUESTION 107
An administrator wants to monitor the health status of an ESX Host. When the host is highlighted in the vSphere Client, the Hardware Status tab is not visible. Which of the following explains the problem and the action needed to resolve this issue?
A.The vCenter Hardware Status Plug-in is not enabled. Enable the Plug-in using the Plug-in Manager
B.The name of the vCenter Server system could not be resolved. Fix the DNS issue or edit the extensions.xml file and replace the vCenter Server name with the IP address
C.The security settings for Internet Explorer are too high. Allow scripting of Internet Explorer Web Browser must be set to Enabled
D.Alarm Actions have not been enabled for this host. Right-Click the host and choose Enable Alarm Actions from the Alarm option
Answer: A
QUESTION 108
Web Access can be used to monitor a virtual machine’s _____. (Choose Two)
A.memory utilization in MB
B.disk utilization in Mbps
C.network utilization in Mbps
D.CPU utilization in MHz
Answer: AD
Explanation:
The screenshot below shows both CPU and memory can be monitored from Web Access. Note that the screenshot is from an ESX host.-
QUESTION 109
Which memory conservation technique allows the secure elimination of redundant copies of memory pages between virtual machines on the host?
A.Memory Balloon Driver
B.VMkernel Swap
C.RAM Overcommit
D.Transparent Page Sharing
Answer: D
Explanation:
Memory Provisioning Recommendations for VMware Infrastructure 3 Operational Best Practices page 7.
Transparent Page Sharing is a process executed frequently by the VMkernel that scans physical memory to identify redundant virtual machine memory pages. When a match is found, the physical page is marked read-only. The VMkernel removes the duplicate page from physical RAM and the page table is adjusted to redirect the virtual machine’s virtual page back to the read-only page in physical RAM. This mechanism results in increasing memory that is shared among running virtual machines over time.
QUESTION 110
What must a system administrator do to enable monitoring of a VM heartbeat with supported third-party SNMP monitoring tools?
A.install VMware tools
B.purchase a separate SNMP license from VMware
C.import VMware MIBs
D.purchase a VMware-aware version of the SNMP monitoring tool
Answer: C
QUESTION 111
The remote console performance for a virtual machine on an ESX Server appears to be degraded. Which of the following could be a possible cause of the problem?
A.The physical NIC assigned to the virtual machine port group containing the affected virtual machine has a speed or duplex mismatch.
B.To conserve memory, the ESX Server has initiated Transparent Page Sharing.
C.The virtual NIC assigned to the virtual machine has a speed or duplex mismatch.
D.The virtual machine has an IP address conflict.
Answer: A
QUESTION 112
The graph shown in the exhibit indicates a problem with which of the following resources?
A.CPU
B.Memory
C.Network
D.Disk
Answer: D
QUESTION 113
The graph shown in the exhibit indicates which of the following?
A.Average amount of time SCSI reads and writes spend in the queue
B.Average amount of time required to read and write from the Guest OS to the Virtual Machine virtual Disk file
C.Average amount of time spent by the VMkernel processing SCSI read and write commands
D.Average amount of time spent reading and writing to the physical storage device
Answer: B