Health and Performance Monitoring Service in VSAN 6.2

Being a VSAN administrator we generally use VSAN observer while troubleshooting VSAN Performance issues. VSAN observer was first introduced in 5.5 U1 GA and is a part of Ruby vSphere console ( RVC )  tool an interactive command line shell for vSphere management. VSAN observer allows to dig deep into VSAN’s performance, see the IOPS, latency, Outstanding I/Os and congestion’s and lot more. The information is provided at different layers in the Virtual SAN stack to help troubleshoot storage performance. Even VSAN Observer is a powerful tool it itself have some drawbacks.

Drawbacks of VSAN Observer :

  • VSAN Observer only provides real-time view of the system. It does not provide any historic performance data.
  • Not integrated with vSphere Web Client
  • VSAN Observers is a complex tool
  • Impacts vCenter Server as the tool is launched via RVC on vCenter Server.

To overcome these drawbacks, in VSAN 6.2 introduced Performance Service to get detailed understanding of VSAN performance. Virtual SAN performance service monitors the performance of your Virtual SAN environment, and investigate potential problems. The performance service collects and analyzes performance statistics and displays the data in a graphical format. You can use the performance charts to manage your workload and determine the root cause of problems. You can view detailed performance statistics for the cluster, and for each host, disk group, and disk in the Virtual SAN cluster. You also can view performance charts for virtual machines and virtual disks.

VSAN Performance service is disabled by default. Turn on Virtual SAN performance service to monitor the performance of Virtual SAN clusters, hosts, disks, and VMs. When you turn on the performance service, Virtual SAN places a Stats database object in the datastore to collect statistical data. The Stats database is a namespace object in the cluster’s Virtual SAN datastore. Performance and Health monitoring of VSAN Components can be performed on Cluster as well as on individual host.

Procedure to Enable VSAN Performance Service

  • Login to vSphere Web Client and navigate to Virtual SAN Cluster.
  • Click on Manage tab and click settings.
  • Select Health and Performance, click on Edit to edit the performance service  settings.

ScreenshotSelect the Turn On Virtual SAN performance service check box. Select a storage policy for the Stats database object and click OK. Screenshot-1

You can see Health and Performance service is enabled and status as Healthy and compliant.

Screenshot-2Performance and Health monitoring of VSAN Components can be performed on Cluster as well as on individual host. Select

  • Virtual SAN – Virtual Machine Consumption : Virtual SAN displays performance charts for clients running on the Cluster / Host, including IOPS, throughput, latency, congestions, and outstanding I/Os.
  • Virtual SAN – Backend : Virtual SAN displays performance charts for the cluster back-end operations, including IOPS, throughput, latency, congestions, and outstanding I/Os.


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This concludes the configuration of Health and Performance service in VSAN 6.2. I hope this is informative for you. Thanks for reading !!!. Be social and share it in social media, if you feel worth sharing it.



Deploy two Node VSAN Cluster using VSAN Configuration Wizard – VSAN 6.2

With VSAN 6.2, VMware simplified the process of deploying VSAN Stretched and VSAN two host cluster. VSAN Stretched cluster allows to protect virtual machines across data centers where as 2-node VSAN is an excellent solution for remote office / branch office (ROBO) configuration. In both the scenarios, a dedicated witness host is required.

Virtual SAN for ROBO use Fault Domains, where in this case the required failure zones are based on three nodes (two physical nodes and witness node). Witness node are used to provide an availability mechanism to virtual machines. Witnesses plays an important role in ensuring that more than 50% of the components of an object remain available. Instead of deploying a dedicated physical ESXi host to be a witness host, as well as consume a license for the witness host, Vmware deployed the VSAN witness appliance to take care of the witness requirements.  There are no licenses needed with the witness appliance, as it comes per-configured with a license. Of course, if you wish to use a physical host for the witness, you can do that too.

If you choose to use witness host as a physical server not a witness appliance, it is required to do the configuration manually on the host.

You should have

  • One flash
  • One capacity disk.
  • One Port Group to have VSAN Traffic enabled.
  • Witness host should not be part of VSAN Cluster

In Lab I have deployed a physical host to be used as Witness host. You can use the Configure Virtual SAN wizard to complete the basic configuration of your Virtual SAN cluster.

  • Navigate to an existing cluster in the vSphere Web Client.
  • Click the Manage tab and click Settings.
  • Under Virtual SAN, select General and click Configure to open the Configure Virtual SAN wizard.

ScreenshotChoose appropriate Disk Claiming technique to your environment.

  • Automatic: Claims all empty devices on the included hosts for Virtual SAN.
  • Manual : Requires manual claiming of the devices on the included hosts.

Choose Two host Virtual VSAN Cluster.  Screenshot-1Configuration Wizard will check if VSAN Traffic is allowed on atleast one portgroup on both the nodes of the cluster.Screenshot-2Mark disk to be used for Capacity / Cache Tier. Click Next.Screenshot-3 Select the node to be used as Witness Host.Screenshot-5Mark the disk for Cache / Capacity Tier on the witness host and click NEXT.Screenshot-6Click Finish to proceed further.Screenshot-8Once configured, one of the node will be marked as Preferred and other will be Secondary.Screenshot-9The virtual machine components will be scattered across nodes ensuring that more than 50% of the components of an object remain available in case of host failure.Screenshot-10


This conclude the deployment of VSAN 2 Node Cluster using VSAN Configuration wizard in VSAN 6.2. I hope this is informative for you. Thanks for reading !!!. Be social and share it in social media, if you feel worth sharing it.