Virtual Serial Port/Remote Serial Console - HP AB500A - Integrated Lights-Out Advanced Technology Brief

an iLO Advanced license for ProLiant ML, DL and SL-systems, but that functionality is included with the
iLO Blade Standard package for ProLiant BL systems.
Administrators can access the iLO Virtual Serial Port using Remote Serial Console in the iLO 2
firmware. They can use the iLO Virtual Serial Port for text console access during POST and OS
operation. The iLO processor contains hardware that can replace the physical serial port on the
server's motherboard, and the iLO firmware provides a Java applet that connects to the server serial
port. If the serial redirection feature is enabled on the host server, iLO intercepts the data coming from
the serial port, encrypts it, and sends it to the Remote Serial Console applet or another application
such as a telnet or SSH client. The iLO 2 Remote Serial Console applet appears as a text-based
console, but the information is rendered using graphical video data.
Access to the iLO 2 Remote Serial Console is a standard feature and does not require a license key.

Virtual Serial Port/Remote Serial Console

Some operating systems, such as Microsoft® Windows® Server 2008 and Linux, provide text-based
access to the server from the host server serial port. An administrator can connect a terminal to the
serial port of the host server and perform basic management tasks. For example, if it is enabled, the
Windows EMS Console displays the processes that are running and allows administrators to halt
processes. This capability can be important in cases where video, device drivers, or other OS features
have prevented normal operation and normal corrective actions.
An administrator can remotely access a console application, such as Windows EMS over the network
using the iLO virtual serial port. As described in the previous section, the iLO management processor
contains the functional equivalent of the standard serial port (16550 UART) register set, and the iLO
firmware provides a Java applet that connects to the serial port. If the serial redirection feature is
enabled on the host server, 2 iLO intercepts the data coming from the serial port, encrypts it, and
sends it to the web browser applet or telnet application.
For Linux users, the iLO virtual serial port feature provides an important function for remote access to
the Linux server. An administrator can configure a Linux login process attached to the serial port, and
then use the iLO virtual serial port to remotely login to the Linux operating system over the
management network.
Additional details about using the Virtual Serial Port are available in the document titled "Integrated
Lights-Out Virtual Serial Port configuration and operation." This is available at:
http://h20000.www2.hp.com/bc/docs/support/SupportManual/c00263709/c00263709.pdf
Digital Video Redirection (DVR) engine operation
The iLO first generation processor acquired management console video by monitoring the PCI bus for
data sent to the video controller. In-band video monitoring is simple, cost effective, and adequate for
emergency or part-time management console operation. As administrators began using iLO remote
console for routine operations in addition to emergency management, improved video monitoring
became necessary. The iLO 2 management processor uses a DVR engine for video capture. The DVR
engine includes a video capture buffer (Figure 3) that monitors the Digital Video Output (DVO) of the
host video controller (not the PCI bus). The DVR engine captures the screen image one stripe at a time.
Linux users must also set up a login shell to the serial port (TTYS0) and configure the host server to allow root
2
access.
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