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This is heavily WIP as long this note is here

Ubuntu 9.04 (jaunty jackalope)

(this howto is based on the Debian Etch iSCSI howto with some major changes)

Introduction

If you are experienced with ubuntu and initramfs / initrd creation you can install ubuntu directly onto the iscsi target using the desktop (i386 or amd64) install CD (more on that later). The alternate install disk is not capable of installing additional packages at runtime, because of the limitations of the busybox environment.

If you have the possibility it is more comfortable to install ubuntu onto a local HDD, USB stick or whatever and boot into the installed system after that.

Assumptions

This howto is based on the following assumptions:

  • An installation of ubuntu or one of its pendants in the latest (jaunty) version
  • the system is installed on a single harddrive, no matter how much partitions you have set up
  • there is an already done iscsi target on an iscsi server
  • there is a working dhcp server (although you will only need it for comfort, configuring gpxe manually does also work)

Preparations

The debian howto recommended to compile open-iscsi yourself as iscsistart and fwparam_ibft were not available in the debian packages that time. This is not necessary for ubuntu for some reasons:

  • fwparam_ibft is no longer a (fully featured) component of neither the open-iscsi semi-stable release (which does not even support kernel 2.6.28+) nor the development git source tree
  • iscsistart is available via open-iscsi from the ubuntu repositories.
  • the initramfs scripts are even prepared for iscsi usage in some way

But the initramfs / initrd has to be recreated to include the required iscsi stuff: (I use joe for some vintage reason, but you are of course free to use the editor of your choice)

install required packages

 sudo aptitude install initramfs-tools open-iscsi

change the initiatorname (of the client) to something unique if you are planning to set up many boxes

 sudo echo "InitiatorName=iqn.1993-08.org.debian:01:22b2ed5d3ccc" > /etc/iscsi/initiatorname.iscsi

touch the indicatorfile, which is queried to determine, whether the daemons are to be copied into the new initrd

 sudo touch /etc/iscsi/iscsi.initramfs

now we have to workaround a bug in the jaunty stable tree, so edit /usr/share/initramfs-tools/hooks/iscsi with your favourite editor:

 sudo joe /usr/share/initramfs-tools/hooks/iscsi
 and change line 25 from:
    copy_exec /usr/sbin/iscsistart /sbin
 to
    copy_exec /sbin/iscsistart /sbin

generate the new initrd('s)

 sudo update-initramfs -u
 update-initramfs: Generating /boot/initrd.img-2.6.28-11-generic

now we have to take care that neither /etc/init.d/networking nor the Network Manager reconfigures the interface again during the init process or X11 startup so edit /etc/network/interfaces:

 sudo joe /etc/network/interfaces
 and change the appropiate entry for your primary NIC from:
    #iface eth0 inet dhcp
 to
    iface eth0 inet manual

As we do not have fwparam_ibft we cannot read out the ibft contents that gpxe has left, so we have to specify vital iSCSI information via Kernel command line options. Use your favourite boot manager for this. I did use grub, because it is preinstalled and my no. 1 choice anyway. Make the boot process verbose if you want to be able to see potential problems immediately when they occur. It could look like this:

 title		Ubuntu 9.04, kernel 2.6.28-11-generic iSCSI
 uuid		f859db1e-39f8-4539-9f0e-8292f8f93cca
 kernel		/vmlinuz-2.6.28-11-generic ISCSI_INITIATOR=iqn.2009-04.arbeitsgruppe:general ISCSI_TARGET_NAME=iqn.2009-04.Arbeitsgruppe.Commander1024:general.ubuntu ISCSI_TARGET_IP=192.168.234.1 ISCSI_TARGET_PORT=3260 root=UUID=021ebcfc-188a-41ba-9864-ee18cbf7af9f ro
 initrd		/initrd.img-2.6.28-11-generic
 quiet

This are the available options (which are parsed from /proc/cmdline):

  • ISCSI_INITIATOR
  • ISCSI_TARGET_NAME
  • ISCSI_TARGET_IP
  • ISCSI_TARGET_PORT
  • ISCSI_TARGET_GROUP
  • ISCSI_USERNAME
  • ISCSI_PASSWORD=
  • ISCSI_IN_USERNAME=
  • ISCSI_IN_PASSWORD=

Doing the final cut

Now your installation is nearly ready to be booted from an iscsi storage, there are only three last minor fixes to do

Transfer your image to the iSCSI Target server


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