VSAN-Troubleshooting-Reference-Manual

Diagnostics and Troubleshooting Reference Manual – Virtual SAN
Navigating VSAN Observer – PCPU
The PCPU tab shows overall CPU usage and also per component CPU usage statistics
of Virtual SAN. This view shows CPU usage from an overall host perspective, as well
as specifically from the view of Virtual SAN wordlets and networking worldlets.
A worldlet can be considered a process that does some work on behalf of Virtual
SAN. A single worldlet can at most occupy a single physical CPU core. The 100%
mark in the graphs refers to a percentage of that limit.
If the utilization of a Virtual SAN worldlet is getting close to 100% then CPU is likely
a bottleneck for Virtual SAN performance. However, even when the utilization is not
yet maxed out, a significant utilization (>10%) of readyTime indicates CPU
contention between Virtual SAN and other uses of physical CPUs on the host (e.g.
running VMs). Looking at overall CPU consumption of the host should confirm this
picture.
Some of the graphs visible on this view are:
Client – amount of CPU consumed by client worldlets; client is the
component which accesses an object on behalf of a VM.
CompServer – amount of CPU consumed by component server worldlets.
This provides the network front-end for accessing an object.
Owner – amount of CPU consumed by owner worldlets. The owner is the
storage head and co-ordinates that can do I/O to an object. Owner
communicates to the component manager to access a leaf on the object’s
RAID tree.
LSOMLOG – amount of CPU consumed by LSOMLOG worldlets.
PLOG – amount of CPU consumed by PLOG worldlets
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