System information

7 Automatic Cluster Management
The maintenance of a computer cluster causes high administration efforts. Often, there are
periodical tasks like set up new cluster node or the inspection of certain hardware com-
ponents which has to be done manually by human intervention. For example, the LDAP
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entry of the Ethernet MAC of a new cluster node or the inspection of the screen content
of a failed computer are performed by the administrator. The CHARM card undertakes
administration tasks of a computer cluster. It inspects periodically the node and takes an
action automatically if necessary. Additionally, the CHARM setups and installs new cluster
nodes. An important basement of the automatic function is the extraction of information
from the screen content of the host computer as describes in section 6.3. The following
sections describe the automatic functions of the CHARM and the way it performs these
tasks.
7.1 Complex Tasks
The CHARM is able to process complex tasks like set up the CMOS content or executing a
program on the host system. Several functional units provide specific features which are used
to process a complex task. Following programs are the base of the complex tasks: terminal,
keyb_cmd, msbod, crsh.sh, hostPowerOn, hostPowerOff, hostReset, hostPOSTcode. These
programs are explained in the appendix C. For its relevance, only the crsh.sh shell script will
be discussed in the following section. The building of shell scripts which perform complex
tasks is exemplified in detail with two automatic functions in section 7.1.2 and section 7.1.3.
7.1.1 CHARM Remote Shell
The CHARM remote shell (crsh.sh) provides the execution of programs on the host system
without using a network connection. Instead, it uses the screen content of the host computer
and the keyboard emulation to get a communication base to the host system. The crsh.sh
script encapsulates the interaction with the host. It takes the parameter command which
has to be executed on the host computer. The output of the command is printed out to the
calling CHARM console. Following is an example of usage of the crsh.sh to get the CPU
information of the host system:
CHARM$>crsh.sh more /proc/cpuinfo
processor : 0
vendor_id : AuthenticAMD
cpu family : 6
model : 6
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Lightweight Directory Access Protocol is a protocol for querying and modifying directory services.
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