The following will illustrate the vSAN upgrade procedure to version 6.6. I have been slowly upgrading my lab to vSphere 6.5 and with it NSX to 6.3 and now vSAN 6.6, as always follow the official upgrade procedure here and see the vSAN 6.6 release notes here.
The first step to patch my PSC and vCenter, my original upgrade was 6.5 GA release but this is not supported with vSAN 6.6 so I will patch to the latest version of 6.5, at the time of writing it 6.5.0e. Release note dictate vCenter and ESXi must be 6.5.0d. Note - direct upgrade from 6.0 Update 3 to 6.5.0d is NOT supported.
My PSC is external so ill update that one first then the vCenter. Thankfully its very easy to patch the virtual appliances, I browse to the following.
https://lab-psc.vjenner.com:5480
I then log on as root an go to Update.
From here I can either attach the iso or point to a repository, by default the repository is online and my appliance can get out to the internet so I will download the patch direct.
Once installed the appliance needs reboot, once rebooted I can now see the patch is installed.
I now need to repeat this for my vCenter. Once upgraded I can now move onto the ESXi hosts.
On my previous post upgrading my vCenter to 6.5 I migrated my Update Manager to the virtual appliance, it only seems fit to upgrade the host using Update Manager. I wont go over each step, the first step is to upload the iso.
I then just create a new Host Upgrade baseline.
I then attach said baseline to the hosts I want to upgrade.
I then simply Remediate the host.
For my environment I first upgraded the hosts to 6.5 GA but I also need to patch the hosts to be able to support vSAN 6.6. Using Update Manager I then apply a new baseline with the latest patches for 6.5.
Once complete my hosts are now running at the right version.
I repeat this process for all of my hosts, once all hosts are on the compatible level I need to upgrade the on-disk format verison to version 5. I go to Web Client - Host and Clusters - Cluster - Configure - vSAN - General - Upgrade.
Agree to the upgrade.
That will then upgrade the disk groups, notice the process of upgrade, remove and re add of the disk groups.
Once complete my vSAN is now v6.6.
Notice on the above picture the networking mode is now Unicast - this automatically changes after the last host is upgraded. Previous version us multicast but from 6.6 onwards it will be unicast.
Im also running NSX, when I check the host status I can see the vib status is still good for the hosts.