What’s new on vSAN 6.6

Today, one of the largest vSAN releases was announced. This release comes packed with new features, enhancements, and a lot of improvements; making vSAN 6.6 easier to deploy with enhanced performance, and a more complete HCI platform.

What’s New with vSAN 6.6?

Native Encryption 

Encryption is one of the main features for this release. This is a software solution rather than just using self encrypted devices (SEDs), which are not needed by the way. Any HCI can add SEDs and call their solution encryption ready, but vSAN goes a step further and provides software encryption for data at rest.

 

vSAN Configuration Assist 

The vSAN configuration assist allows customer to check hardware compatibility, conduct burn-in tests, check network and vSAN configurations, as well as getting recommendation for optimal cluster configuration based on current status. For example, the configuration assist will check to make sure all vSAN vmknics are configured properly, as well as recommending upgrading on-dik format to the latest versions. Such recommendations will allow for a configuration that follows vSAN best practices.

 

Hardware Lifecycle Management

This feature allows customers to be able to update outdated controller firmware and driver version for example. In such case the outdated hardware will be identified and you will have the option to download and install the latest version directly from the vSphere Web Client. This feature removes the need for vendor-specific tools as it provides an orchestrated hardware lifecycle management across the vSAN cluster.

 

Host Client vSAN visibility

Although vSAN is not heavily dependent on vCenter, in the event that vCenter is not available we lose some visibility from the UI perspective. On vSAN 6.6, the HTML5 Host Client now has visibility and capability of doing health checks not only for the host itself but also for the entire cluster.  Alternatively you can use “esxcli vsan” commands for additional tasks. Such commands have been expanded to keep up with the new features.

 

Web Client Health and Performance Monitoring 

The vSAN health function has now significantly more checks to aid in proper configuration and troubleshooting. Monitoring and alerts have also been added for the new features such as physical disk health, networking, etc. On the performance diagnostics side,  you are now able to query throughput, latency, and IOPs among others.

 

Host Evacuation Pre-checks 

Built into maintenance mode operation and disk/disk group removal, the pre-check allows for lower operational overhead, and reduces risk by helping ensure proper capacity remains after a host evacuation. The pre-check will show if there is sufficient capacity for data movement and how much data will be moved. I really like this feature as it gives visibility to the “What-if” for each option of maintenance mode.

 

Easy Deployment 

The new VCSA is now capable to deploy a vSAN cluster on a single node and place the VCSA appliance on the vSAN datastore. This eliminates the need for external storage, forgoing to claim disks, or bootstrap scripts. This makes greenfield deployments quick and easy for vSAN clusters.

 

Multicast Dependency REMOVED 

Yes! Another big step here. The need for multicast is no longer required. In fact, once you upgrade your vCenter and hosts to version 6.6 the networking mode is automatically changed to unicast.

Proactive Drive HA 

vSAN 6.6 intelligently predicts device failure and proactively move data out of the failing device before it actually fails and cause a Permanent Device Loss action.

 

 

Other Great Additions:

  • vRealize Management Pack for vSAN
  • Easier replacement of witness host on stretched-clusters
  • vSAN API and PowerCLI enhancements
  • Local Failure Protections for Stretched Clusters through Primary and Secondary FTTs
  • Stretched Cluster Site Affinity
  • Deduplication and Compression Performance Enhancements
  • Checksum optimization
  • Rebuild & Resync Enhancements (Partial Rebuilds)
  • Proactive and more aggressive de-staging

 

I’ll be writing a few more blogs about the new features. Stay tuned.

 

VSAN 6.2 Performance Degradation (Hybrid)

In vSAN (not misspelled) 6.2, dedup and compression was introduced. These features; however, only apply to all-flash configurations and must not be set up on Hybrid environments.

Some customers have experienced performance degradation on 6.2 Hybrid environments when compared to 6.0 or 6.1 performance. Read caching performance degradation can be observed for Hybrid Disk Groups on the SSD cache tier, due to a low level scanning for unique blocks (dedup). Although this is normal for All-Flash environments, it is important to check your hosts participating on a Hybrid Cluster, to make sure this is turned OFF.

To check/change this option, you can use the ESXi Shell or PowerCli.

The setting would show “2” if it is turned ON, and “0” if it is turned OFF. It should be set to “0” for EACH Hybrid host.

Check Setting

ESXi Shell – esxcfg-advcfg -g /LSOM/lsomComponentDedupScanType 

lsom_shell_check

 

 

PowerCli – Get-VMHost<HostName> | Get-AdvancedSetting –Name LSOM.lsomComponentDedupScanType

lsom_pcli_check

 

 

 

Change Setting

ESXi Shell – esxcfg-advcfg -s 0 /LSOM/lsomComponentDedupScanType 

lsom_shell_change

 

 

PowerCli – Get-VMHost <HostName> | Get-AdvancedSetting -Name LSOM.lsomComponentDedupScanType | Set-AdvancedSetting -Value “0”

lsom_pcli_change

 

Using PowerCli is my preference, since you won’t have to enable SSH on the hosts, and you can use wildcards to check/change all the hosts with little effort.