I installed vCenter 5.5 appliance recently as part of a test lab. It is installed on ESXi 6.0 and I am trying to upgrade to 6.5 but I only have an ISO for 6.5. have tried putting the ISO in the CD/DVD drive in ESXi then booting the vCenter appliance to do the upgrade. It is not booting to the ISO and just skipping it. The connected setting is checked so it should be seeing it. Suggestions on what to try? I have never done an upgrade for vCenter before.
The vCSA ISO image isn't bootable. The way to upgrade vCSA 5.5 to 6.5 is to mount the ISO image to e.g. a Windows system, and start the istaller from the vcsa-ui-installer\win32 directory. This will launch the installation wizard, which will guide you trough the upgrade. What basically happens, is that a new vCSA is deployed on the ESXi host, and the configuration is migrated from the old vCSA.
That presents a bit of a problem, I can't boot two VMs on the bare metal host without issues of memory. It is not I don't have enough memory but the data store is full and creating another one isn't working so the swap file is stuck. Is there not a way to do it without needing the vcenter vm open and a windows one too.
The upgrade procedure requires the old vCenter to be available to pull the configuration for the new one. The system from where you run the installer however, can be your local PC (i.e. not a VM).
To save disk space on the datastore (since this is a lab this should be ok) you may consider to set a memory reservation for existing VMs to reduce the required disk space for the VMs' swap files.