View source for IRIDIA cluster installing the diskless nodes

This section is on how to install the diskless nodes from scratch. That includes setting the server up so that serves the diskless nodes. If you are simply adding a new node, then many of the steps described on this page are not necessary.

Let's  get started.

=== Installing a new diskless image ===
Install the package called diskless and diskless-image-simple on majorana:
<pre>
apt-get install diskless
apt-get install disklass-image-simple
</pre>

This packages contain tools and binaries for a Debian image for the diskless nodes. 

Create a new image:
<pre>
diskless newimage
</pre>
For more information on creating see http://wiki.debian.net/index.cgi?DiskLess

In order to create the individual directories for each node, run the script:
<pre>
/root/bin/update-host-directories
</pre>

You should configure the image to not use devfs:
<pre>
chroot /var/lib/diskless/default/root
dpkg-reconfigure -p low diskless-image-simple
<answer with the default except for what concerns devfs>
exit
update-host-directories
</pre>

=== Compiling a new kernel for the diskless nodes ===
On majorana, download the source code of the kernel which you installed. It should end up in /usr/src. Now use the config file of the kernel you installed on majorana (see [[IRIDIA cluster installing an OS on the servers]]) found in /root/.config to compile a kernel for the diskless nodes.

<pre>
cd /usr/source/[kernel-dir]
make menuconfig
exit
copy /root/.config .
make menuconfig
</pre>

At least four options should be changed, don't use modules, compile everything into the kernel:
* Initial ramdisk (initrd) should be disabled in '''device driver -> block devices''')
* Mount NFS as root:
** Enable '''File systems -> Network File Systems -> NFS file system support'''
** Enable '''File systems -> Network File Systems -> Root file system on NFS'''
* Assign IP address at boot time:
** Enable '''Device drivers -> Networking Support -> Networking Options -> IP: kernel level autoconfiguration -> IP: DHCP support''' 
* Compile GigaBit network driver into the kernel: 
** Set: ''' Device Drivers->Networking support->Ethernet (1000Mbit)-><*> Intel(R) PRO/1000 Gigabit'''

Furthermore, the kernel needs a slight change in the source code, so that the kernel requests an address via DHCP after during load:

In net/ipv4/ipconfig.c change:
<pre>
int ic_enable __initdata = 0;
to:
int ic_enable __initdata = 1;
</pre>

You are know ready to make a .deb package containing the kernel image:
<pre>  	  
make-kpkg --append-to-version -dc kernel_image kernel_headers 
</pre>

Now you are ready to install the new kernel in the diskless image. The following sequence of commands should do the trick:
<pre>
cd /usr/src
mv *deb /var/lib/diskless/defaut/root/root
chroot /var/lib/diskless/default/root/
cd root
dpkg -i *deb
exit
</pre> 

Whola! The new kernel should be installed in the diskless image.