Virtual SAN performance Service: What is it? (And what about these other things)
One of the newest exciting features of Virtual SAN 6.2 is the new performance service. This is an ESXi native performance monitoring system with API, as well as UI access.
One misconception I wanted to be clear on is that it does not require the use of vCenter Operations Manager, 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 want the overhead of VSOM this is a great solution, and will complement the existing tools.
Now why would you want to deploy VSOM if this turnkey simple, low overhead performance system is native? Quite a few reasons:
- VSOM offers longer term granular performance tracking. The native Virtual SAN performance service uses the same roll up schedule as vCenter’s normal performance graphs.
- VSOM allows for forecasting and capacity planning as it analysis trends.
- VSOM allows overlaying performance from multiple area’s and systems (Including things like switching, application KPI’s) to do root cause and anomaly analysis and correlation.
- VSOM offers powerful integration with LogInsight allowing event correlation with performance graphs.
- VSOM allows for rolling up performance information across hundreds (or thousands of sites) into larger dashboards.
- In heterogenous enivrements using traditional storage, VSOM allows collecting fabric, and array performance information.
So if I don’t enable this service (or deploy VSOM) what do I get? You still get basic Latency, IOPS, throughput information from the normal vCenter performance graphs by looking at the vDisk layer. You miss out on back end component views (things like internal SSD queues and latency) as well as datastore/cluster wide metrics, but you can still troubleshoot basic issues with the built in performance graphs.
What about VSAN Observer? For those of you who remember previously this information was only available by using the Ruby vCenter shell interface (RVC). VSAN observer provides powerful visibility, but it had a number of 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, or to deploy 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.
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.
Virtual SAN Performance service also offers “bottom up” visibility into device latency and queues on individual capacity and cache devices. 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.
vCenter 6.0u2 (For UI)
Up to 255GB of capacity on the Virtual SAN datastore (You can choose the storage policy it uses).