System information

10 Conclusion and Outlook
This thesis has presented a powerful remote management device which is suitable for the
most of the IBM compatible computer systems. The basic concept of the system is to
provide an independent and reliable off-band remote management facility. The remote
device, called CHARM card, is usable in a heterogeneous computer cluster environment to
provide a generic and uniform remote management interface for the administrator. The
administrator can work on every node as if sitting in front of it. By the reason of the PCI
and USB interface, the CHARM is flexible while emulating human interface devices. For
example, if USB is not available on a system, the CHARM can use the PCI interface to
interact with the computer. The basic functions of the card are accessible with common
applications like a web browser or a VNC client without the need for a special client software.
Furthermore, the card assists the administrator and undertakes periodical administration
tasks like set up of a cluster node, reboot of a crashed system or search of the failure of a
malfunctioning computer. This feature is enabled by the novel method consists of exporting
the screen content. Common remote management cards or KVMs use present graphic cards
to get the screen content. The analog signal of the graphic card is digitalized and sent to
the management computer. Few remote devices integrate a graphic processor, but finally
use the output signal of the graphic processor to generate the screen image. In contrast, the
CHARM card does not convert the received VGA information into a video signal. Instead, it
uses the raw VGA data to generate an image of the screen. The advantage of this approach
is that the VGA data information can be more rapidly transformed into an image than the
digitalization of a video signal. Furthermore, the VGA video planes can be inspected to get
a textual content of the screen. Running an alphanumeric mode, the video planes already
contains ASCII characters. Graphical modes has to be inspected with an optical character
recognition (OCR) program. But at boot time, the computer BIOS uses mainly the font set
provided by the graphic card. In this case, the character recognition is very simple, because
the font set is already known. However, if the BIOS does not use the font table of the
graphic card, the font table of the related BIOS has to be find out one-time with common
OCR software. Subsequently, the CHARM can use this table on every computer using the
same computer BIOS. The textual representation of the screen provides the semantic of
the screen content. This enables the generation of scripts running on the CHARM and
undertake complex administration tasks on the host computers: for example, the setup of
the BIOS settings or the installation of a cluster node. The status of the program running on
the host can be obtained by the screen content. Thus, the inspection of the screen and the
interaction via an emulated keyboard enables the automation of a variety of administration
tasks independently of the running software or operating system.
The CHARM card achieves an acceptable frame rate presenting the host screen to control
the computer by remote. Although the VGA processing is done by software on an embedded
system, the usability of the CHARM is sufficient for the computer remote control. However,
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