How to roll back or downgrade VMware 4.x to 3.x
The chance that you might have to do this in the future are pretty small. I can’t think of too many reasons that you might need to rollback your upgraded host. But in case you do I have put together a few steps to show you the way. Make sure to read the risks and understand what you might be in for.
Risks and Considerations
Any changes made to the ESX 4.x service console are lost after the rollback.
Changes made to virtual machines (such as an installation of VMware Tools) persist after the rollback.
If you upgraded the virtual machine hardware, the virtual machines will not work after you perform the ESX rollback. To avoid this situation, take a snapshot of the virtual machines before you upgrade the virtual machine hardware. After you run the ESX rollback script, boot into ESX 3.x and revert to the snapshot.
Only perform the rollback if you are very familiar with the ESX environment and are comfortable running commands from the service console.
Follow these steps to roll back your installation from 4.x to 3.x
Do not perform this process until you have read and understand the Risks. This cannot be reversed.
1. Log onto the service console as Root
2. Run this command: rollback-to-esx3
Note: This command reconfigures the bootloader to boot into ESX 3.x and removes the ability to boot into ESX 4.0. You can include the optional -f (force) flag. If you omit the -f flag, you are prompted to confirm that you want to roll back to ESX 3.x.
3. Next issue the reboot command or a “shutdown -r now” will also work.
Note: When the host is powering on, you can see that the boot menu has reads ESX 3.x.
4. After the host boots into ESX 3.x, you can safely delete the ESX 4.0 service console VMDK folder from the VMFS datastore. The service console VMDK folder name has the format esxconsole-<UUID>.
About Brian Suhr
Brian is a VCDX5-DCV and a Sr. Tech Marketing Engineer at Nutanix and owner of this website. He is active in the VMware community and helps lead the Chicago VMUG group. Specializing in VDI and Cloud project designs. Awarded VMware vExpert status 6 years for 2016 - 2011. VCP3, VCP5, VCP5-Iaas, VCP-Cloud, VCAP-DTD, VCAP5-DCD, VCAP5-DCA, VCA-DT, VCP5-DT, Cisco UCS Design