It ran successfully and I rebooted into ESXi-6.7.0-20221004001-standard.
Here's the weird part: It only works for one boot. If I reboot the machine again, it boots back into ESXi-6.7.0-20220704001-standard! I can rerun the update and get back into 20221004001, but again, another reboot brings it back to 20220704001.
I do notice that while booted into 20221004001, /altbootbank isn't being mounted anymore. I thought I'd try to outsmart it by booting back into 20220704001 and cp'ing /altbootbank/* to /bootbank/, but that broke booting with a no hypervisor found error. So I did a refresh reinstall and.. I'm back to the same situation. Any ideas? Has anybody else seen this before?
Dude, that's some serious head-scratching material you've got there. I haven't personally run into this exact issue, but it sure sounds like a roller coaster. The flip-flopping between versions after reboot is definitely strange.
Your mention of /altbootbank not being mounted is a big red flag for me. Normally, ESXi swaps between /bootbank and /altbootbank during updates, and if /altbootbank isn't being used, that could explain the weird version flip-flopping you're seeing.
Have you checked to see if the contents of /bootbank and /altbootbank are actually different after the patch but before the reboot? Maybe comparing the contents could shed some light on what's going wrong.
If you've got the courage for it, you could look into manually editing the boot.cfg files in each bank. It's risky, but you might be able to force it to boot from the version you want.
If nothing else works and you haven't already, I'd take this to VMware support or at least post on the VMware communities to see if anyone else has encountered this strange issue. Sometimes these obscure problems turn out to be known bugs, and someone out there might have a patch or workaround.