Vnx-rootfsfedora

How to create a Fedora root filesystem for VNX

(being updated...do not use...)

Follow this procedure to create a fedora based root filesystem for VNX. The procedure has been tested with Fedora 16 and 14.

Basic installation

• Create the filesystem disk image:

qemu-img create -f qcow2 vnx_rootfs_kvm_fedora.qcow2 8GB

• Get Fedora installation DVD (use the complete DVD; do not use the Live version, as it seems the installation wizard does not include the customization menu). For example:

wget ftp://ftp.rediris.es/mirror/fedora/16/Fedora/i386/iso/Fedora-16-i386-DVD.iso
cp Fedora-16-i386-DVD.iso /almacen/iso

• Create the virtual machine with:

vnx --create-rootfs vnx_rootfs_kvm_fedora.qcow2 --install-media /almacen/iso/Fedora-16-i686-Live-Desktop.iso --mem 768M

• Follow the Fedora installation assistant. At some point, you will have to choose among different system profiles: desktop, web server, minimal, etc.
• Enable login on the first serial line:
• Fedora 16. Execute this command:

ln -s /usr/lib/systemd/system/getty@.service   /etc/systemd/system/getty.target.wants/getty@ttyS0.service

• Fedora 14. Create a file named /etc/init/serial-ttyS0.conf with the following content:

#This service maintains a getty on /dev/ttyS0.
start on stopped rc RUNLEVEL=[2345]
stop on starting runlevel [016]
respawn
exec /sbin/agetty /dev/ttyS0 9600 vt100-nav

And add ttyS0 to /etc/securetty file if you want to login root on that console:

echo "ttyS0" >> /etc/securetty

• Finally, delete the net udev rules file and halt the system:

rm /etc/udev/rules.d/70-persistent-net.rules
halt -p

Configuration

• Restart the system with the following command:

vnx --modify-rootfs vnx_rootfs_kvm_fedora.qcow2 --update-aced --mem 768M

Note: ignore the errors "timeout waiting for response on VM socket". 768M are needed if you are installing a root filesystem with desktop interface

• Access the system through the text console to easy the copy-paste of commands:

virsh console vnx_rootfs_kvm_fedora.qcow2

• Check that you have network connectivity. Maybe you have to activate the network interface by hand:

dhclient eth0

Note: use "ip link show" to know which network interface to use.

• Update the system and install additional packages

yum update
yum install perl perl-XML-DOM acpid udisks

Note: if yum fails, check that the network is working. Maybe you will have to manually execute "dhclient eth0", at least in the case of a minimal installation.

• Install VNX autoconfiguration daemon:
• From the host execute:

/usr/share/vnx/bin/vnx_update_aced Fedora /usr/share/vnx/aced/vnx-aced-lf-0.1b.tgz 

• From the virtual machine console:

ln -s /media/CDROM /media/cdrom
udisks --mount /dev/sr0
perl /media/cdrom/install_vnxaced

• If you have chosen a "minimum installation", activate network services (they are disabled by default):

chkconfig --level 3 network on

• Optionally:
• Install other services needed, for example, an apache server:

yum install httpd
update-rc.d -f apache2 remove   # to avoid automatic start

• Or, if using a "minumum installation", install network utilities:

yum install telnet wget openssh-clients

• If you want automatic login, just edit /etc/gdm/custom.conf and add the following lines:

AutomaticLoginEnable=true
AutomaticLogin=vnx

• Disable the firewall. Firewall is enabled by default; that could be problematic for testing purpose systems. If desired, disable it graphically in "System|Administration|Firewall" option, or using the following command from the command line:

chkconfig iptables off

• Create a file /etc/vnx_rootfs_version to store version number and informacion about modification:

VER=v0.21
OS=Fedora 14
DESC=Basic Fedora 14 root-filesystem without GUI

• Create a script named /usr/local/bin/vnx_halt:

#!/bin/bash
# Clean yum cache
yum clean all
# Delete /etc/resolv.conf
rm -f /etc/resolv.conf
# Clean command history
rm -f /root/.bash_history
# Delete udev net rules files:
rm -f /etc/udev/rules.d/70-persistent-net.rules
# Delete VNXACE log
rm -f /var/log/vnxaced.log
while true; do
    # Ask for a message to save in /etc/vnx_rootfs_version file
    echo    "** Save a log message in /etc/vnx_rootfs_version file "
    echo -n "** describing the modifications done? "
    read -n 1 -p "[y/n] " answer
    echo ""
    case $answer in
        [Yy]* )
                echo "** Log message (1 line maximum):"
                read logmsg
                DATE=`date`
                echo "MODDATE=$DATE" >> /etc/vnx_rootfs_version
                echo "MODDESC=$logmsg" >> /etc/vnx_rootfs_version
                break;;
        [Nn]* ) break;;
        * )     echo "** Error: please answer 'y' or 'n'.";;
    esac
done
# Halt the system
halt -p

• Give the script execution permissions:

chmod +x /usr/local/bin/vnx_halt

• Stop the machine with that script:

vnx_halt

Installing additional software

To install additional software or modify your root filesystem, you just have to start it as described above and make the operations required on the filesystem.

• Start the virtual machine (directly using virsh or the vnx_modify_rootfs utility):

 /usr/share/vnx/bin/vnx_modify_rootfs rootfs_fedora.xml 

• Install the software:

yum install ...

• Stop the machine with:

vnx_halt