Helping Hand Questions for 5V0-22.21

The maximum time range that can be stored by the vSAN health check history is 180 days (C). According to the VMware Official Guide, “The vSAN Health Check history is stored for up to 180 days before it is automatically purged.”

vsantop is a command line utility that can be used to monitor the performance of a vSAN cluster in real-time. It provides detailed information about the performance of the vSAN cluster and its components, including disk usage, IOPS, network traffic, and object states. It can be used to identify the root cause of performance problems, such as disk contention, network congestion, or object failures. It provides a quick and easy way to identify the root cause of performance issues, making it a useful tool for troubleshooting vSAN clusters.

This is explained in VMware vSAN documentation in the section "vSAN Tools and Troubleshooting" Reference: https://docs.vmware.com/en/VMware-vSphere/7.0/vsphere-vsan-70-admin-guide/GUID-7E8F6C98-7C0B-4D21-8F1A-F3A3A9F4F4A4.html

Minimum number of hosts required for Raid 5: 2n+1.

Reduced availability - active rebuild: The object has suffered a failure, but it was configured to be able to tolerate the failure. I/O continues to flow and the object is accessible. vSAN is actively working on re-protecting the object by rebuilding new components to bring the object back to compliance.

Reduced availability with no rebuild: The object has suffered a failure, but VSAN was able to tolerate it. For example: I/O is flowing and the object is accessible. However, VSAN is not working on re-protecting the object. This is not due to the delay timer (reduced availability - no rebuild - delay timer) but due to other reasons. This could be because there are not enough resources in the cluster, or this could be because there were not enough resources in the past, or there was a failure to re-protect in the past and VSAN has yet to retry.