Vnx-rootfsfedora

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Revision as of 00:48, 22 May 2012 by David (talk | contribs) (Basic installation)
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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 8G
    
  • 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-i386-DVD.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:
  • mount /dev/sdb /mnt/
    perl /mnt/vnxaced-lf/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
      chkconfig httpd off  # if you want to avoid automatic start of apache server
      
    • 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
      chkconfig ip6tables off
      
    • Change grub timeout to 0 by editing /etc/default/grub file and setting:
    • GRUB_TIMEOUT=0
      

      and executing:

      grub2-mkconfig -o /boot/grub2/grub.cfg  
      
  • Create a file /etc/vnx_rootfs_version to store version number and informacion about modification. For example:
  • VER=v0.24
    OS=Fedora 16
    DESC=Basic Fedora 16 root-filesystem without GUI
    
  • Finally, stop the virtual machine with:
  • vnx_halt
    
    vnx_halt deletes some caches and log files and optionally lets you write a short message to /etc/vnx_rootfs_version file describing the latest modifications done.

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

Known problems