Exam 5V0-21.21 topic 1 question 42 discussion

A is correct

AS per my previous notes

A for sure Storage Controller Queue Depth There are two important items displayed by the VCG for storage I/O controllers that should be noted. The first of these is “features” and the second is queue depth. Queue depth is extremely important, as issues have been observed with controllers that have very small queue depths. In particular, controllers with small queue depths (less than 256) can impact virtual machine I/O performance when vSAN is rebuilding components, either due to a failure or when requested to do so when entering maintenance mode. Design Decision : Choose storage I/O controllers that have as large a queue depth as possible. While 256 are the minimum, the recommendation would be to choose a controller with a much larger queue depth where possible. https://core.vmware.com/resource/vmware-vsan-design-guide#sec6843-sub14

A is correct. Verify that the queue depth of the controller is 256 or higher. Higher queue depth provides improved performance. source: https://docs.vmware.com/en/VMware-vSphere/7.0/com.vmware.vsphere.vsan-planning.doc/GUID-475FAD6E-2A1A-443A-82AC-FCA35D916032.html B is wrong as cache should be disabled or ser 100 to read C is wrong as this is used in normal RAID config D Raid 0 is an option to set up vSAN on some old controllers but this is not a performace solution

For sure this is not D. I think it is A.