So the issue occurs when upgrading from x86_64 generic minimal flavor Photon 3 to Photon 4 ?
There were some issues with upgrade from Photon 3 to Photon 4, have a look to open/closed issues @ https://www.github.com/vmware/photon .
Could you add the journalctl log when opening the issue ticket? Try to give as much case information as possible.
The /tmp screen message was reproducible on the testlab, the freeze not (?).
December 13th 2022, edited:
In the testlab, I've installed x86_64 ESXi8 virtual hardware for Photon OS virtual machine, photon-minimal-3.0-a0f216d.iso (Photon OS 3.0 Revision 2 Update2 Binaries).
I've tried this:
yum upgrade
tdnf install -y photon-upgrade
photon-upgrade.sh --upgrade-os
Just as comment: Better use tdnf e.g. tdnf distro-sync because tdnf is the preferred package manager on Photon OS.
The picture attached is right before the reboot. The reboot was successful, 2nd reboot, too.
The issue described unfortunately wasn't reproducible in the testlab.