If an ESXi 5.1 host does not successfully install, serial line logging can be configured when booting the installer using advanced kernel boot-time parameters. This takes effect for the current boot, and does not persist across future reboots.
To enable serial-line logging during installation:
- At the Loading ESXi installer screen, press Shift+O.
- At the prompt, append the advanced option to specify a serial port after runweasel:
> runweasel debugLogToSerial=1 logPort=com1
- Press Enter to boot.
- Logging starts after the first loading progress bar finishes.