Home > ESX, VMware > Enable Serial-Line Logging on ESX 3.5 through HP iLO

Enable Serial-Line Logging on ESX 3.5 through HP iLO

First we need to configure the Virtual COM port.

Reboot your server and get into the BIOS by pressing F9.  Get into the System Options screen and select the Virtual Serial Port.  Take a note of the COM port used (COM 2 in this example).


Go back to the main menu and select BIOS Serial Console & EMS.  Under BIOS Serial Console Port, select the COM port you noted above.  Set the BIOS Serial Console Baub Rate to 115200.

Boot the server into ESX.  Edit the file /boot/grub/grub.conf and add the option to the kernel line: (if the options are already there, modify if needed).

I prefer modifying only the boot entry for VMware ESX Server (debug mode).  This way you can always boot ‘normally’ with the first boot option.

If you use nano to modify the grub.conf file, make sure to specify the –w parameter so nano doesn’t wrap the text!

console=ttyS1,115200 console=tty0

Fire up you vCenter Client and go to the Advanced Settings under Configuration of the ESX Host.

Edit the Misc.SerialPort and Misc.SerialBaudRate settings to match your Virtual COM port (COM 1 = 1, COM 2 = 2).


Reboot the server and select the correct boot entry to boot ESX with serial-line logging enabled.

Start PuTTY and connect to the iLO address over SSH (port 22).  If needed, specify Logging options to log all output to a text file (which is mostly the case if you enable serial-line logging).


Enter your iLO username/password (not your ESX user!).  If all goes well, you get the iLO Command Prompt.

Type the following command to enter Virtual Serial Port mode.  Press ESC + ( to exit the Virtual Serial Port).


The PuTTY screen will be loaded with LOTS of debug logging.  Enjoy reading it 🙂

Categories: ESX, VMware
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