Cloning ESXi boot devices is not supported. While this may have worked successfully in previous versions of ESXi, there are additional dependencies on the System UUID being unique on ESXi 7.0 U2 and moving forward. See the official statement about cloned ESXi boot device supportability here:
https://kb.vmware.com/s/article/84280Workaround:
If you are running ESXi hosts that have cloned boot devices in your environment, there is a 4 step process to change the System UUID on each server so that it will be unique. It should be noted that this process will only work on hosts that have not been upgraded to ESXi 7.0 U2 yet. If hosts have already been upgraded to 7.0 U2 then the only supported solution is rebuild those hosts.
Note: This will not work on the original host with the correct MAC address in the UUID.
1. There is an advanced ESXi setting called FollowHardwareMac that will automatically update the VMkernel's MAC Address whenever the network adapter MAC Addresses changes. To do so, you will need to run the following ESXCLI command:
esxcli system settings advanced set -o /Net/FollowHardwareMac -i 1
2. The other modification that is required is to delete the existing System UUID entry in /etc/vmware/esx.conf configuration file. This will ensure a new System UUID will automatically be generated when the system boots up and written to this file. To do so, open esx.conf and delete the entire /system/uuid line entry and then save the file. Alternatively, here is a one-liner you can run without needing to open up VI in order to clear this line in the config file:
Note: Run this exactly. ## is part of the command and does not represent numbers.
sed -i 's#/system/uuid.*##' /etc/vmware/esx.conf
3. To ensure that this change is persisted, run the following command:
/sbin/auto-backup.sh
4. Reboot the ESXi host to generate the new System UUID. It is important to verify that the System UUID has actually changed from the original.
Note: All datastores affected by corruption will need to be reformatted to clear the corruption. This should be done AFTER changing the UUID on ALL ESXi hosts otherwise corruption will continue.