I have a preference to do brand new installs of ESXi for each new release. With new releases there are new options, new features, and caveats with existing functionality. This means the migration process takes longer, but it helps ensure that I’m applying current best practices each and every time instead of applying upgrades to a flawed design.
In some instances this isn’t a concern and we can use vCenter with Update Manager to upgrade hosts to the latest version of ESXi and preserve our current configuration (name, IP, storage, etc). I use this process when remotely upgrading Hosts in my colo facility without having console access to the physical servers.
This is a step by step guide to creating an upgrade baseline to upgrade an existing ESXi Host (5.0 for this writing) to 5.5 and begin the upgrade process on a Host.
1. Existing host running 5.0 or 5.1 connected to vCenter Server 5.5
2. vCenter Server 5.5 with Update Manager installed
3. Downloaded .ISO of ESXi 5.5
1. Using the vSphere thick client (not web client), connect to the vCenter server and click the “Home” button followed by “Update Manager” under “Solutions and Applications”
2. Click on “ESXi Images” tab
3. Click the link for “import ESXi Image” to wards the top right corner
4. Click “Browse” and locate the .ISO of ESXi, click “Open” then click “Next”
- a. If you receive a security warning, click the check box to install the certificate and click “Ignore”
- b. The ISO should upload. When completed click “Next”
5. Enter the name of this upgrade baseline identifying the version in the name or description then click “Finish”
6. Click the “Home” button followed by “Hosts and Clusters”
7. Click on the Host to be upgraded and then click the “Update Manager” tab
8. Click the “Attach” link towards the top right corner
9. Place a check in just the upgrade baseline created and then click “Attach”
10. Click the “Remediate” button towards the lower right corner
- a. Confirm Upgrade baselines and the ESXi 5.5 baseline are selected then click “Next”
- b. Accept the license agreement and click “Next”
- c. Leave “Remove installed third-party software” unchecked and click “Next”
- d. Leave the schedule as “Immediate” and click “Next”
- e. Since this host is not in a cluster, choose “Power off virtual machines” and click “Next” (THIS WILL POWER OFF ANY VMS THAT ARE ON THAT HOST)
- f. Click the “Finish” button
11. This process takes awhile and you’ll lose access to the server while it is remediating. If you have access to the console during this time, it is a good idea to have it open and watch the progress.
Once the upgrade is complete the Host will be available within vCenter and will be running ESXi 5.5. Once completed, make sure you double-check your settings (time, network, DNS) to ensure all your settings are still there. Also, take this time to attach your patches baseline and get the latest patches applied to this Host.