Assuming that ballooning is possible, under which three circumstances might the VMkernel use a swap file for a running virtual machine?
A.
The Mem CtlMaxPercent value is between 10 and 25 percent
B.
Memory cannot be reclaimed quickly enough
C.
The virtual machine is starting up
D.
VMware Tools is not installed
E.
50 percent of the configured memory has already been balooned
“Assuming that ballooning is possible” scores out vmtools installed.
“MCTLMAX”: the maximum amount of guest physical memory that the balloon driver can reclaim. Default is 65% of assigned memory. D is wrong
not very clear
“Assuming that ballooning is possible” scores out The virtual machine is starting up.
A and D are wrong too (based on the 65% default). So the only 100% correct answer is B
I’d still go with B,C and D.
C is out coz the question is about “a swap file for a running virtual machine?”. Answer C is about a VM which is “starting up”.
D is ridiculous because memory will be swapped out whether VMware Tools is installed or not depending on the allocated memory vs the memory reservation.
The vswap file gets created at some point when the power on task hits 95%, and it’s deleted immediately during the power off task. It could be argued that the power on task creates a world PID and thus the process is “running.” If it were to get hung then you would kill the world PID.
Also, ballooning occurs _inside_ the guest and relates to a page file or swap partition, not vswap. That makes E irrelevant for sure.
I hate this question.
Good tricky question.
C, D is definitely out of question. The question says “Assuming ballooning is possible”. For ballooning “memory balloon driver (vmmemctl) ” to work VMWARE Tools should be running. VMWARE Tools cannot be running if the virtual machine is starting up or not installed.
http://www.vmwarearena.com/2012/08/verify-memory-balloon-drive-status-of.html