Gentoo Linux on Intel SCC
We have created a Gentoo Linux suitable for running on the Intel SCC. You can download it here: scc_gentoo_20101117.tar.zst.Installation
Un-tar the archive, then copy the contents of theshared folder to your own /shared file system. The package
contains the following:
| File | Notes |
/shared/gentoo/
|
Gentoo root filesystem |
/shared/to_gentoo.sh
|
Script to enter Gentoo |
/shared/set_nat.sh
|
Script to configure the MCPC as a NAT router |
Usage Overview
This Linux has been built such that it can be used on the SCC as well as on the MCPC itself. In both cases, we rely on an already running Linux kernel, then use chroot to exchange the user mode environment. This works fine on both the default SCC Linux (2.6.16-mcemu) as well as the MCPC Ubuntu kernels (2.6.32 and later, compiled for x86_64).
To enter Gentoo, execute /shared/to_gentoo.sh. This will mount
/proc and /dev into the Gentoo root, then open
an interactive shell. If you are running on an i586 kernel (SCC
Linux/"uname -m" returns "i586"), it will also start some daemons.
From within Gentoo, all usual Linux tools are available. Please
note that Gentoo uses Portage for package management, so you need
to invoke emerge instead of aptitude
when installing or updating them. For more details on
emerge, please refer to the Gentoo
Handbook, especially the
Portage introductiongoo. When installing new or updated
packes, emerge usually wants to download the
respective sources; to give your SCC access to the MCPC's primary
network connection, execute /shared/set_nat.sh
as root on the MCPC. The script
assumes that eth0 is the primary (WAN) connection,
whereas the SCC cores are connected via eth1 (LAN),
so it enables NAT routing from eth1 to
eth0. If your network setup is different, please
change the corresponding defines in the script. (For example, if
you are using sccKit 1.3.0 or earlier, your SCC cores are
connected via crb0 instead of eth0,
because your FPGA won't be able to use the RockyLake board's
ethernet ports. In this case, change the definition of the
LAN interface to crb0). If everything
is set up correctly, you should be able to do something like
ping www.intel.com from the SCC, and
emerge should also get access to its repositories.
X11 Redirection
Our Gentoo comes with X11 installed, so you can use X11 redirection to run your applications on the SCC while displaying the user interface on a different machine (e.g., the MCPC).
We use ssh's built-in X11 redirection, but this requires
xauth on the server (the
machine running sshd).
As this depends (obviously) on X11, which is not delivered in the
standard SCC Linux distribution, we chose to start a second ssh
server when Gentoo is running. This is done automatically when
running to_gentoo.sh on
the SCC, so you usually don't need to do anything special. The
second sshd listens on port 1234. Therefore, to start an ssh session
with X11 redirection, you can simply use the following command on
the MCPC:
ssh -Xp 1234 jan@rck00
This works once Gentoo has been started on the respective SCC node
(rck00 in the example).
It opens an ssh connection that automatically forwards X11 to the
client. As a first test, try running xeyes. The user jan (the password, in case you ever need it, is
identical to the name :) can use su and sudo freely to perform actions as root.
Ganglia
As the SCC can be seen as cluster-on-a-chip, we also included support for Ganglia, a famous monitoring system for clusters.
When starting Gentoo on the SCC, it also starts the gmond, Ganglia's node monitor
daemon. gmond is
configured to send its data to the MCPC (via the rckhost alias), but in order to view
the data, you'll also need a Ganglia installation on the MCPC
itself. To do so, install the packages gmetad and ganglia-monitor via Ubuntu's packet management,
then use our configuration files gmetad.conf
and gmond.conf
for the daemons on the MCPC (make a backup of the default files in
/etc/ganglia first). To
be able to view the gathered data, you need to insert something like
the following line at the end of your /etc/apache2/apache.conf:
alias /ganglia
/usr/share/ganglia-webfrontend
After restarting Apache, point your web browser to http://localhost/ganglia to view
your cluster status (the MCPC will be considered one node in the
"DCL-RockyLake" cluster; feel free to change the name to anything
you like :).
For this setup to work, both gmetad and gmond (named ganglia-monitor on Ubuntu) need to be running on
the MCPC, and the gmond
instances on the SCC need to be started after the
MCPC daemons (otherwise, some metrics simply aren't available). To
make sure the daemons on the MCPC start at boot time, you can use a
command like sudo rcconf --on
gmetad,ganglia-monitor.