Virtual SAN Performance Service and Performance Tools

One of the exciting new features of Virtual SAN 6.2 is the new performance service. For quick troubleshooting of issues, or verification of performance it is a great and simple tool that can be turned on with a single checkbox.  This is an ESXi native performance monitoring system with API, as well as UI access. For those of you interested in the VSAN API check out William Lam’s excellent blog post covering it, as well as links to SDK’s for Ruby, Java, Python, C# and Pearl SDK’s. Some enthusiastic customers have been using this API for some time to pull VSAN into 3rd party systems.

The Performance UI

Click to expand!So the question remains what do you get when using the new VSAN performance service on its own? Quite a bit! There is an extensive amount of metrics that can be reviewed. It offers “top down” visibility of cluster wide performance, and virtual machine IOPS and latency.


You can view Latency, IOPS, throughput information all using the normal vSphere client without need for a 3rd party interface. Cluster level views and virtual machine views give a “top down” view of the infrastucture  allowing for quick checks of virtual machine performance an demands.


Screen Shot 2016-05-08 at 3.59.02 PMBottom up visibility is extended through component level views that expose cache hit rates, write buffer usage, and individual device latency. This allows you to quickly isolate a faulty drive, and confirm that the low level components of your Virtual SAN cluster are performing properly.For quick troubleshooting of issues, or verification of performnace it is a great and simple tool that can be turned on with a single checkbox.

In order to enable it simple follow these instructions and make sure your ESXi hosts and vCenter are running at 6.0update2 or newer. Note the Database can use up to 255GB of capacity, and a VSAN SPBM policy is set/created for this database.


vRealize Operations Manager

One misconception I wanted to be clear on is that the performance UI does not require the use of VMware vRealize Operations Manager (vROPs), or the vCenter database. Instead, Virtual SAN performance service uses the Virtual SAN object store to store its data in a distributed and protected fashion.  For smaller environments who do not need vRealize Operations Manager this is a great solution, and will complement the existing tools. For larger environments it will still provide quick tactical views into performance visibility.

Now why would you want to deploy vROps if this turnkey simple, low overhead performance system is native? Here are a few really good reasons:

  • vROps offers longer term granular performance tracking. The native Virtual SAN performance service uses the same roll up schedule as vCenter’s normal performance graphs.
  • vROps allows for forecasting and capacity planning as it analyzes trends.
  • vROps allows overlaying performance from multiple areas and systems (Including things like switching, application KPI’s) to do root cause and anomaly analyzes and correlation.
  • vROps offers powerful integration with LogInsight allowing event correlation with performance graphs.
  • vROps allows for rolling up performance information across hundreds (or thousands of sites) into larger dashboards.
  • In heterogeneous environments using traditional storage, vROps allows collecting fabric, and array performance information.
  • vROps has deep integration with other VMware products like Horizon View allowing you to look at user level login events, VMware Infrastructure, and external infrastructure (Such as WAN routers or load balancers) in the same dashboard. SAP, Oracle, SQL, EPIC and other business critical applications need end to end visibility.

It should be noted no hyperconverged or monitoring offerings offers as many VMware and 3rd party integrations for performance monitoring. Other solutions only monitor individual applications stacks, are limited only limit to the hardware and hypervisor.


VSAN + vROps Licensing Consideration

One thing to note is that if you are using the Management Pack For Storage Devices for VSOM purely for VSAN you only need the standard licensing for VSOM. Per the VMware Product Guide

Customers who purchased a license of VMware Virtual SAN Standard, VMware Virtual SAN Advanced, VMware Virtual SAN Standard for Desktop, VMware Virtual SAN Advanced for Desktop, or VMware Software bundles that include VMware Virtual SAN may enhance the use of the Software with the Management Pack for Storage Devices (MPSD) only in the same Clusters licensed to run the VMware Virtual SAN Software.


VSAN Observer

VSAN-Observer-PCPU-ViewWhat about VSAN Observer? Previously to look at detailed performance information we had to leverage the Ruby vCenter shell interface (RVC). VSAN observer provides powerful but had these limits:



  • It was designed originally for internal troubleshooting and lacks consistency with the vCenter UI.
  • It ran on its own web service separately and was not integrated into the existing vCenter graphs.
  • It was manually enabled from the RVC CLI
  • It could not be accessed by API
  • It was not recommended to run it continuously on the vCenter, and required a separate Virtual machine/Container to run it from.

All of these limitations have been addressed with the Virtual SAN performance service.

I expect the performance service will largely replace VSAN Observer uses. VSAN observer will still be useful for customers who have not upgraded to VSAN 6.2 or where you do not have capacity available for the performance database. Today the Performance UI offers powerful deep views into cluster, virtual machine, host and hardware performance. vCenter Operations Manager extends this visibility in a single pane of glass allowing application owners to see problems coming as well as under stand their cause.


Leave a Reply

Your email address will not be published.