There is a new whitepaper provide by VMware which teaches you how to monitor VMware VSAN with a VMware VSAN Observer. It's a utility which is baked in with vCenter server (since 5.5 U1) and which allows to dig deep into VSAN's performance, see the IOPS, latency, Outstanding I/Os and congestions etc…
It's quite complex tool when you first start it. Even for starting it up, you must know how to do it (see my how-to) as it's part Ruby vSphere Console (RVC). The RVC console wasn't public from the start. The tool was used exclusively by VMware VSAN development team before it was released to public.
I have setup VSAN observer and took a first look at it, like how to start the tool and see the dashboard, but the author – Rawlinson Rivera (in collaboration with Christian Dickmann, Mousumi Millick, Joe Cook and Charu Chaubal) goes much deeper and shows for example 3 different modes you can start VSAN observer in:
- Live monitoring for a Virtual SAN cluster
- Offline Monitoring
- Full Raw stats bundle
The paper is destined to VMware administrators leveraging VSAN in their environments. The paper is a real good resource.
I'm going to use myself to see how my own homelab VSAN installation performs.
The PDF is 44 pages long. You'll learn about many things. For example:
- Outstanding IOs
- Virtual SAN Architecture
There are good explications to start with:
IOPS gives a measure of number of Input/Output Operations Per Second of a storage system. An I/O operation is typically a read or a write and a size. I/O size can vary from anywhere between a few bytes and several megabytes.
Outstanding I/O – When a virtual machine requests for certain IO to be performed (reads or writes), these requests are sent to storage devices. Until these requests are complete they are termed outstanding I/Os.
The paper is full of graphics. This one is just general VSAN observer graphic, but many screenshots from the UI details every menu item so you can really master the tool.
As said, the paper treats every menu of the VSAN observer tool:
- VSAN Client
- VSAN Disks
- VSAN Disks (deep dive)
- DOM Owner
The paper also provides 4 examples of workflows and each example then explains with screenshots where to look and how-to read the performance metrics! This is very valuable.
You can download this paper from this post. Enjoy…