Abstract

I typically cover more open source technology on this blog, however, I recently upgraded our high availability ESXi hosts for work and thought it would make a good blog post because of the configuration and process that was taken to accomplish the goal.

Pre-upgrade tasks

Before performing the upgrade, there are some things that should be done ahead of time to make the process as smooth as possible. This, in no particular order, is what my list for prepping for this upgrade was.

• Blank flash drives
• Download ESXi installation ISOs and burn to flash drives for install media
• Download vCenter upgrade ISO and have Windows machine on the same network as server(s)
• Backup configuration of each of the ESXi servers
• Confirm credentials for vSphere and ESXi servers
• Make sure to have correct licensing

Confirming and practicing recovery

While upgrading ESXi should go smoothly, there is not really a way to guarantee there will not be any problems, which is way it is always good practice to create a backup and practice the restoration before everything blows up. Thankfully, there is documentation on how to create a backup and restore from the backup available here. Then to make sure it worked follow these steps:

1. vMotion all running VMs to other server
2. Shutdown server and replace running drive with blank drive
3. Boot from ESXi installation media and install 7.0.3 (current version)
4. Restore configuration

Assuming the host came backup as if nothing happened we are good to proceed.

Upgrading vCenter

Upgrading vCentter was a bit of a nothing burger for me, as the old VM that runs the vCenter appliance is not destroyed or modified during the upgrade procedure. From VMware’s website on the GUI upgrade (which is what I used):

The GUI upgrade is a two stage process. The first stage is a Deployment wizard that deploys the OVA file of the new appliance on the target ESXi host or vCenter Server instance. After the OVA deployment finishes, you are redirected to the second stage of the process that sets up and transfers the services and configuration data from the old appliance to the newly deployed appliance.

Now, that doesn’t mean that nothing can go wrong; weird stuff happens all the time, but that is what backups are for (you do have backups, right?).

Performing upgrade

Upgrading ESXi should be a fairly straightforward task, however, after version 7.0.3, VMware added a system requirement that the OS must be installed on a SATA, SAS, or NVME drive. Our server only had a USB drive, however, we fortunately had an old unused server that had drives that could be repurposed. Each of the ESXi hosts were given two drives to have a RAID-1 mirror for the host OS. From there, install 7.0.3 to the new RAID-1 mirror and restore the configuration as done above. Then the upgrade can be performed; the upgrade method I used was the interactive upgrade.

The actual upgrade process is also rather straightforward; simply booting the 8.0.0 install media and selecting the drive that the current ESXi installation is on will prompt for an upgrade. Reboot the machine once the upgrade is finished and make sure to license the machine as it will likely require a newer license. Since my company has two servers running in high availability, it was necessary to vMotion all the running VMs over to the now upgraded 8.0.0 host and repeat the process on the primary server.