Debian Diskless Setup and Configuration

Here we are going setup a server that serves over network to pxe clients a diskless debian. We will be using the following:

• DHCP server: dh1 (see how to install here)
• TFTP server: tftp1 (IP: 192.168.10.35)
• NFS server: nfs1 (IP: 192.168.10.30)
• PXE image location on NFS server: /srv/diskless/c1

DHCP Server

1. Allow issue ip addresses to pxe clients:

   subnet 192.168.10.0 netmask 255.255.255.0 {
     pool {
       range 192.168.10.101 192.168.10.199;
     }
     option subnet-mask 255.255.255.0;
     option broadcast-address 192.168.10.255;
     option routers gw1.dev.local;
     
     allow bootp;
     allow booting;
     next-server tftp1.dev.local;
     use-host-decl-names on;
     if substring (option vendor-class-identifier, 0, 9) = "PXEClient" {
       filename "pxelinux.0";
     }
   }
   

2. If you wish dhcp server to serve same ip address to the clients, here are few lines to add. Note that if you need the client to be accessable via its name (c1) you need to add a record to dns server (since the ip address served by dhcp is the same it is fine to add it do dns).

   host c1 { 
     # this is client MAC address
     hardware ethernet 00:1D:77:7B:F8:19; 
     fixed-address 192.168.10.101;
   }
   

TFTP Server

1. Install the following packages (it is fine to use lxc container if any):

   apt-get -y install syslinux tftpd-hpa
   

2. TFTP default directory location:

   root@tftp1:~# cat /etc/default/tftpd-hpa | grep TFTP_DIRECTORY
   TFTP_DIRECTORY="/srv/tftp"
   

3. PXE configuration:

   # Copy files for pxe boot
   cp -r /usr/lib/syslinux/pxelinux.0 /srv/tftp
   cp -r /usr/lib/syslinux/menu.c32 /srv/tftp
   # create configuration folder
   mkdir /srv/tftp/pxelinux.cfg
   

4. Prepare initramfs to boot over nfs (this step and one that follows needs to be run on machine that has a kernel you are going to serve to your clients, e.g. lxc container doesn't have this so you need to run it on host)

   cp -r /etc/initramfs-tools /etc/initramfs-pxe
   cat /etc/initramfs-tools/initramfs.conf | \
       sed "s/BOOT=local/BOOT=nfs/" > \
       /etc/initramfs-pxe/initramfs.conf
   

5. Copy kernel and make nfs specific changes to initrd image:

   cp /boot/vmlinuz-`uname -r` /srv/tftp
   mkinitramfs -d /etc/initramfs-pxe -o \
       /srv/tftp/initrd.img-`uname -r` `uname -r`
   

   The above changes gave me following:

   tftp1:~# ls -hl /srv/tftp/
   initrd.img-2.6.32-5-amd64  pxelinux.0  
   pxelinux.cfg  vmlinuz-2.6.32-5-amd64
   

6. Now it is time configure default pxe configuration (file /srv/tftp/pxelinux.cfg/default):

   DEFAULT menu.c32
   
   PROMPT 0
   TIMEOUT 100 
   NOESCAPE 1
   ALLOWOPTIONS 0
   
   MENU TITLE PXE Network Boot Menu
   
   LABEL c1
       MENU LABEL Debian GNU/Linux, with Linux 2.6.32-5-amd64
       KERNEL vmlinuz-2.6.32-5-amd64
       APPEND root=/dev/nfs quiet panic=0 initrd=initrd.img-2.6.32-5-amd64 nfsroot=192.168.10.30:/srv/diskless/c1 ip=dhcp rw
   
   LABEL local
       MENU LABEL Boot Local Hard Drive
       LOCALBOOT 0
   

   At this point PXE client should be cable to load and boot the kernel image.

NFS Server

NFS server doesn't work in lxc container, so choose host machine.

1. Install necessary packages:

   apt-get -y install nfs-kernel-server nfs-common
   

2. Create a root mount point for pxe clients:

   mkdir /srv/diskless/c1
   

3. Let NFS server know about it (file /etc/exports ):

   /srv/diskless/c1  192.168.10.0/255.255.255.0(rw,sync,no_root_squash,no_subtree_check)
   

5. Issue the following command so it exported:

   exportfs -a
   

6. It is recommended to tune the following kernel parameters (file /etc/sysctl.conf):

   # Default OS receive buffer size for all types of
   # connections.
   # net.core.rmem_default = 229376
   net.core.rmem_default = 1048576
   
   # Max OS receive buffer size for all types of 
   # connections.
   # net.core.rmem_max = 131071
   net.core.rmem_max = 1048576
   #
   # Default OS send buffer size for all types of 
   # connections.
   # net.core.wmem_default = 229376
   net.core.wmem_default = 262144
   
   # Max OS send buffer size for all types of 
   # connections.
   # net.core.wmem_max = 131071
   net.core.wmem_max = 262144
   

   Configure kernel parameters at runtime:

   sysctl -f
   

PXE Client

1. This is run on NFS server since it will serve root fs ro PXE clients:

   apt-get -y install debootstrap
   

2. Create debian minimal installation:

   debootstrap --arch amd64 testing /srv/diskless/c1
   

3. Change mount options for the client (file /srv/diskless/c1/etc/fstab):

   proc            /proc         proc    defaults 0 0
   /dev/nfs        /             nfs     defaults 0 0
   none            /tmp          tmpfs   defaults 0 0
   #none            /var/run      tmpfs   defaults 0 0
   #none            /var/lock     tmpfs   defaults 0 0
   none            /var/tmp      tmpfs   defaults 0 0
   none            /media        tmpfs   defaults 0 0
   none            /var/log      tmpfs   defaults 0 0
   

4. Configure network interface (file /srv/diskless/c1/etc/network/interfaces):

   auto lo
   iface lo inet loopback
   iface eth0 inet dhcp
   

5. Copy timezone files and kernel modules from host:

   cp /etc/timezone /srv/diskless/c1/etc/timezone
   cp /etc/localtime /srv/diskless/c1/etc/localtime
   cp -r /lib/modules/2.6.32-5-amd64/ /srv/diskless/c1/lib/modules/
   

6. Here we install few packges (not we chroot to client root file system).

   chroot /srv/diskless/c1
   apt-get update
   apt-get -y install ifupdown locales libui-dialog-perl \
       dialog isc-dhcp-client netbase net-tools iproute vim \
       apt-utils
   

7. Configure locale

   echo "en_US.UTF-8 UTF-8" >> /etc/locale.gen
   locale-gen en_US.UTF-8
   update-locale LANG=en_US.UTF-8
   dpkg-reconfigure -u tzdata
   

8. If the machine name is served by dhcp server than /etc/hostname must be empty:

   echo "" > /etc/hostname
   

   otherwise give machine name:

   echo "c1" > /etc/hostname
   

9. Set root user password:

   echo "root:root" | chpasswd
   

Exit client chroot environment.

You should be able now load the minimal debian over network.

Gnome Desktop

That is pretty easy (chroot to /srv/diskless/c1):

tasksel install gnome-desktop --new-install

Troubleshooting

It is strongly recommended remove tracker package since it just kills NFS server IO. Check if you have it installed:

dpkg --list | grep tracker

... and get rid of it:

apt-get remove --purge tracker