Upgrade ESXi 7.0 to 8 Lifecycle Manager | ESXi 7 to 8 Upgrade | vSphere 7 to 8 Upgrade|VMware 7 to 8

What happened, if we have multiple VMs under this esxi , which we are upgrading, all vms will go down, what to do in prod environment before esxi upgrade?

Thank you, one question please, once we will start remidiate host and then it will go to maintenance mode, what should we do for virtual machine which is hosted on this esxi host,. It will also go down in upgrade period of esxi. How to keep all virtual machine live without distrubing.