I'm having an issue upgrading an ESXi 7.0 update 2 ( ESXi-7.0U2a-17867351-standard) to update 3c via the iso file. When the computer boots into the iso image it fails right after loading tools.t00 with error 10, out of resources. Now I will preface this with the fact that I'm running ESXi on an old whitebox that's not listed as compatible hardware, but it's quite generic and has worked for the past ten years (it's an Intel DQ77KB motherboard with a 3770S CPU and 16 gb of memory). I use this in my second home to run a few Linux VMs that serve as the backup site for my one person consulting business, so I really don't need anything more powerful than this.
I've read several things about this error occurring with other versions of ESXi when installing from the ISO and they seem to center around either incompatible hardware, too many adapters, bios settings, or not booting with UEFI. I had an old pcie wifi card and an extra usb adapter on the motherboard, so I removed them with no effect. The bios doesn't have much in the way of settings for how memory is used, so the only setting I could change was to reduce the video memory from 128M to 32M, which didn't fix the problem.
I am legacy booting, although the bios does support UEFI. I didn't try setting it to UEFI because I was concerned that if it worked, what would happen when the upgrade ran against an ESXi installation that wasn't UEFI and perhaps I'd end up with an unbootable system. Am interested if anyone knows if the upgrade would change the boot records to UEFI if I did that.
Also, I know I could run the upgrade from the offline bundle and I suspect that the upgrade would finish, but I was concerned that the system might hang at exactly this same spot upon reboot, as I'm under the impression that the boot sequence for the iso is the same as what the system on disk would use after an upgrade. If that's not the case, then I could try that. I guess I could also try using the offline bundle without the tools, if the problem is actually related to loading tools.t00.