An administrator notices that 8 out of 10 virtual machines have memory ballooning and swapping. However, virtual machine 9 is not ballooning or swapping and
virtual machine 10 is not ballooning but is swapping.
Which two statements explain the behavior of virtual machine 9 and virtual machine 10? (Choose two.)
A.
Virtual machine 9 has a 100% memory reservation.
B.
Virtual machine 10 has a memory limit configured.
C.
Virtual machine 9 has memory shares set to HIGH.
D.
Virtual machine 10 does not have VMware Tools enabled or installed.
Explanation:
Explanation/Reference:
A and D are correct regarding memory ballooning.
Verify that VMware Tools is installed on each virtual machine. The balloon driver is installed with VMware Tools and is critical to performance.
http://pubs.vmware.com/vsphere-60/index.jsp#com.vmware.vsphere.monitoring.doc/GUID-88CA95AD-A583-4EF6-838E-D92C87B0BB00.html
A is correct regarding swapping, because when you reserve 100% memory, actually it´s like disabling Swap files.
http://serverfault.com/questions/460466/how-to-disable-swap-files-in-esxi
‘A’ as making 100% memory reservation means that the ballooning driver never actually kicks in and is effectively disabled. All VM’s memory is mapped to the ESX host RAM.
Swapping however may still occur –inside– the VM at times when there’s no enough memory configured for that VM.
Working link:
https://docs.vmware.com/en/VMware-vSphere/6.0/com.vmware.vsphere.monitoring.doc/GUID-88CA95AD-A583-4EF6-838E-D92C87B0BB00.html
B.Virtual machine 10 has a memory limit configured.
Could also be correct for VM, limts cause swapping.
what is the correct answer?
AB or AD?
I’m pretty sure it’s AD, because swapping is a “last resort” after balloon has been tried. Since the balloon is not being used, it must not be able to.
https://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1033115
I’m going to say A&D also. Looking at the publication that Aegra posted, it shows that the ballooning drive is installed with VMware tools. So if tools are not installed ballooning will not happen.