With any storage system, it is very important to be able to examine performance information and gain insight into the workload. This is particularly true for VSAN, as its distributed nature means that a VM performance problem could be due to the workload, a problematic host, a problematic disk, or other issues.
There are some options available to monitor VSAN performance in vCenter Server and VMware vRealize Operations, but VSAN also ships with a tool called VSAN Observer that can help provide information about VSAN performance. This is invoked via RVC and used via a Web browser. To use VSAN Observer in live mode (where we examine real-time data), the RVC server must have access to the Internet to assist with chart rendering.