System information

1.5 CHARM Card

Common remote maintenance devices use existent management facilities of the main-board.

For the most part the devices access the BMC of the main-board via an IPMB. The absence

of an IPMB limits the features of the device or makes these devices unusable. Furthermore,

the most remote control devices provide solely a KVM function. In addition, monitoring

features or capabilities to inspect the computer are missing on the remote control cards.

The CHARM was developed to archive the required remote access, monitoring and diagnose

capabilities of a cluster of computers such as the HLT. The CHARM is a low proﬁle PCI

expansion card and it is installed to every node in the cluster (ﬁgure B.1 and B.2 of the

appendix B shows an image of the card). Thereby, the card can be used independently of

the computer model or hardware architecture. The sole requirement for the CHARM is the

existence of a Conventional PCI bus. The card combines a number of features needed for

the remote control and remote diagnose of computer systems which are introduced in the

next paragraphs.

1.5.1 Features of the CHARM

The CHARM operates entirely independently of the PC and can remain powered while

the PC may even be powered down. In view of the fact that the CHARM runs with

its own operating system, it can oﬀer a wide range of automatization features, including

automatic installation of the operating system, changing BIOS settings or booting a rescue

disk. There is no need for an administrator to process these tasks. Additionally, the card

provides monitoring and diagnostic features like temperature measurement and POST code

analysis [33]. The board of the CHARM contains several multipurpose interfaces which are

adjustable to later requirements. For example, the BIOS setting of the FEPs’ mainboards

have to be cleared via a jumper after a BIOS update. The mainboard manufacture does

not guarantee a runnable system after a BIOS update if the BIOS setting is solely cleared

by the BIOS update utility. A cable can be connected from the CHARM to the clear switch

in order to reset the BIOS setting by remote control.

The following list gives an overview of the features of the CHARM:

• KVM function.

• Inspecting of the screen content.

• Providing of a boot device via USB.

• Remote power control of the host computer.

• Temperature monitoring with own sensors.

• Fan speed measurement.

• PCI voltage measurement.

• Read out of the CMOS and DMI

contents.

Desktop Management Interface.