Symptoms:
Host reboot process cannot be completed with message:
VMware vSphere ESXi 7.x
This issue is introduced in ESXi 7.0U3c (19193900)
This issue is resolved in ESXi 7.0 U3l (21424296) and later releases.
Workaround:
Once the ESXi host reaches the hung state, the ESXi host will need to be rebooted via DCUI or remote console.
To avoid this issue from re-occurring; enable per file I/O scheduling: