vSAN 6.6.1 introduces below new features:

• Performance Diagnostics
• VMware vSphere Update Manager (VUM) integration
• Device Serviceability enhancement
• Improved vCenter and unicast behaviour for cluster membership

Performance Diagnostics

Another new feature is the performance diagnostics tool. The new tool is designed to examine the results of a performance benchmark like HCI bench, Proactive Tests that have previously been run on your vSAN configuration, and share guidance for how can we improve the performance of the benchmark . The feature offers advice such as increasing a stripe width, adding more VMs or bringing more disk groups into use to improve performance. To use this feature ,Customer Experience Improvement Program (CEIP) and vSAN Performance Service to  e enabled . Once these have been configured, and the diagnostic information has been gathered for approx. 1 hour, benchmark results can then be examined to see if the maximum number of IOPS, maximum throughtput or minimum latency has been achieved. If not, guidance is provided on how best to achieve these objectives in a benchmark run.

Note :- First Enable CEIP then VMware Performance Service

 

Refer KB  for more tests and check .

Improved vCenter and unicast behaviour for cluster membership

In vCenter 6.6 , If vCenter is down and changes are then made to the cluster, when vCenter recovers, it may reset those cluster changes .With vSAN 6.6.1 vCenter is now the “source of truth” for cluster membership , there is a new property for vSAN called “configuration generation”. This addresses the issue of tracking vSAN membership and will avoid the previously described situation.

The actual detection requires the introduction of a “configuration generation” tracking, that covers both changing of vCenter as well as reverting the same vCenter back to an older DB.  This “configuration generation” consists of a vCenter Server UUID, integer generation ID and a timestamp.

VMware vSphere Update Manager (VUM) integration

vSAN 6.6.1 is fully integrated with VUM to makes sure your vSAN cluster is up to date. Using information from the VMware Compatibility Guide (VCG) [also known as the Hardware Compatibility Guide (HCL)], as well details about the underlying hardware, VUM provides appropriate build recommendations for updates, including drivers versions and patch updates. The recommended builds ensures the hardware compatibility of your vSAN deployment is maintained.

Improved Health check Feature

With vSAN 6.6.1 health check has been updated to include checks for new features like update manager (VUM)

Improvements in device serviceability

To Simplify  tasks like hardware maintenance, vSphere includes plugins that provide extended management and information support for physical drives connected to the local storage controllers in a server. For vSAN environments, this capability proves to be especially beneficial. As a result, information, such as drive location in the server chassis, can be displayed through these plugins to ease administration and maintenance.

For select hardware, vSAN 6.6.1 takes this capability one step further by introducing the ability to locate a specific drive and then blink its LEDs to assist with physically locating the drive.

As a result, an admin can visually identify the device that needs attention so they can take proper action—knowing that they are removing the correct physical drive. Admins can use this feature to reduce the time to service a storage device and lower the risk of human error.

Note : This capability works in both RAID mode and pass-through mode, and is currently supported on HPE DL and ML series servers with Gen 9 controllers.