This is not a comprehensive guide on upgrading to vSphere 6. If that is your intention, this is what you should read
Derek Seaman’s guide to vSphere 6.0
This is just my notes on upgrading a few 5.5 hosts to 6. The rule of thumb is that your vCenter version should be equal or greater than ESXi. We already have a vCenter 6 running.
The preferred method of upgrading on a large scale is to use Update Manager. I used ISO for this upgrade. Since the HW is Cisco, I downloaded a Cisco custom ISO from VMware website. I verified the checksum to save time in case the downloaded ISO is corrupted.
sha256sum Vmware-ESXi-6.0.0-3380124-Custom-Cisco-18.104.22.168.iso fe2c494c39f02fef0ed4262761051079f2b9d23e7487eaf6814b0743495f4c5c Vmware-ESXi-6.0.0-3380124-Custom-Cisco-22.214.171.124.iso
I compared the checksum computed with the checksum in VMware website and found them to be matching. I have also disabled monitoring for the hosts. The hosts in this exercise are a single host cluster, hence I had to take the VMs down.
Open the Server KVM console and map the ISO to the CD Drive. Reboot the server and if the server is configured to boot from CD/DVD, will boot from the ISO.
Welcome screen. Hit enter to continue
ESXi is installed on SD card. So this should be storage for upgrading.
Really upgrade? Yes, of course.
It took under a minute to upgrade
Upgrade done! Remove the ISO and hit enter to reboot
THis host is now on ESXi 6.0 U1
[root@rtfmp:~] vmware -lv VMware ESXi 6.0.0 build-3380124 VMware ESXi 6.0.0 Update 1
Notice the prompt is no longer just a #. PS1 now defaults to a format found in some Linux distros.
[root@rtfmp:~] echo $PS1 [root@\h:\w]