I will start by saying I’d absolutely recommend upgrading ESXi in place for ease and speed, but I understand you probably have specific reasons for installing clean versus upgrading. I have seen the act of actually upgrading become much more popular (versus in the past with older versions) over the past few years as the ESXi footprint has become lighter and more robust, but I know you may be changing a lot of your architecture during upgrades in these versions since so much has changed in the vSphere world!
Anyway… (For more detail, please also reference the “Upgrading Zerto Virtual Replication Best Practices” guide located on the myZerto Technical Documentation page, including detail around upgrading the ESXi hosts on the recovery site.)
[Option 1] Upgrade in place:
1.) VMotion VMs from first host, then power down the Zerto VRA. (Enter Host Maintenance Mode)
2.) Upgrade the ESXi host in place.
3.) Power on the VRA and test the host behavior and/or ZVR behavior by adding and protecting some test VMs on this host. (Prevent other VMs from running on this host by remove host from DRS, or using anti-affinity rules, etc).
4.) Once deemed successfully tested and functional, reinstate the host back into production use and migrate desired VMs back to the host.
5.) Repeat on remaining hosts.
[Option 2] “Upgrade” through fresh ESXi install:
1.) Migrate all VMs from the ESXi host.
2.) Use ZVM to remove the VRA from this host (using the UI or automation).
3.) Install and configure host with new ESXi version.
Harry S.
