Scientific Linux / CentOS 如何制作自己的 LiveCD

Scientific Linux / CentOS 如何制作自己的 LiveCD  

http://www.livecd.ethz.ch/build.html

Building your own LiveCD

The build scripts provided here should allow you to build your own Scientific Linux Live CD. This scripts (with some modifications) are also used to build the  CentOS 4 Live CD. You can either install Scientific Linux on a normal PC and use this system as a build system for your livecd. Or you can build the LiveCD in a chroot environment as described below.

WARNING: Do not run the build script on your PC ! On ly run it on a special build PC or in the chroot environment !! The build scripts will change the system and will/can make your system unusable.

Some parts of the following description are taken from  How to make a CentOS 4 Live CD. You will need root access for many of these steps (for chroot and mount) but it is designed to not impact your main install. The build is done in a single directory.

No special livecd kernel is required. The standard Scientific Linux kernel can be used. You just have to install the unionfs and squashfs kernel modules for SL4 and aufs kernel modules for as SL5 as described below.

• Download my build scripts from http://www.livecd.ethz.ch/download/build:
  
• You need squashfs and unionfs support. Here you find RPMS and SRPMS of unionfs/aufs and squashfs: 
  http://www.livecd.ethz.ch/download/RPMS
  http://www.livecd.ethz.ch/download/SRPMS

• The build scripts are also available from a subversion repository. The complete repository can be found athttps://svn.iac.ethz.ch/pub/livecd. The development branch is in https://svn.iac.ethz.ch/pub/livecd/trunk.
• Or you can access the repository by WebSVN under https://svn.iac.ethz.ch/websvn/pub/wsvn/livecd.
• An anonymous subversion checkout of the trunk can be done with

  svn co https://svn.iac.ethz.ch/pub/livecd/trunk livecd-trunk
  

• Start with a working Scientific Linux 4/5 system. You will need a working yum setup.
• Make a new directory to build in, for example

  LIVE=/scratch/livecd
  mkdir -p $LIVE
  

• You need about 4 GB free space in the directory $LIVE to build a live CD having the size of 700 MB.
• Make some subdirectories

  cd $LIVE
  mkdir dev proc sys etc tmp 
  

• Create some files to avoid error messages later

  touch etc/fstab etc/mtab
  

• Mount some virtual filesystems. If you reboot, you will have to redo this step

  mount --bind /dev dev
  mount null -t proc proc
  mount null -t sysfs sys 
  

• Copy your existing yum.conf and /etc/yum.repos.d directroy into the new etc directory:

  cp -a /etc/yum.conf $LIVE/etc 
  cp -a /etc/yum.repos.d $LIVE/etc/
  

• Create directory for rpm transaction lock:

  mkdir -p $LIVE/var/lock/rpm
  

• Install the system with yum like this:

  yum -c $LIVE/etc/yum.conf --installroot=$LIVE install yum rootfiles shadow-utils \
  bind-utils gnupg vim-enhanced vixie-cron crontabs passwd which kudzu dhclient \
  pciutils eject alsa-utils mkisofs wget kernel grub
  

• This should install around 130 packages for a total of about 110-150 MB.
• Enable the use of shadow passwords

  cd $LIVE
  sed -i "s|\*|x|" etc/passwd
  sed -i "s|^root::|root:x:|" etc/passwd
  cat etc/passwd | cut -d":" -f 1 | while read u; do echo "$u:*:12345:0:99999:1:::"; done >> etc/shadow
  chmod 600 etc/shadow
  

• And for /etc/gshadow

  cp -a etc/group etc/gshadow
  sed -i "s|:x:|::|" etc/gshadow
  sed -i "s|:[0-9]\+:|::|" etc/gshadow
  chmod 600 etc/gshadow
  

• To allow choosing different keyboard layouts install

  yum -c $LIVE/etc/yum.conf --installroot=$LIVE install kbd system-config-keyboard
  

• To install a basic graphical environment (x-server, login manager, windows manager)

  yum -c $LIVE/etc/yum.conf --installroot=$LIVE install system-config-display gdm xterm icewm
  

• Without the package "system-config-display", the x-server will be not correctly configured !
• Install further rpms using yum, for example to add KDE

  yum -c $LIVE/etc/yum.conf --installroot=$LIVE install kdeartwork kdebase \
  kdegraphics kdelibs kdemultimedia kdenetwork kdepim kdesdk kdeutils
  

• You will have to play around until you find which packages you need.
• For example to access remote Linux systems you may want to add openssh client

  yum -c $LIVE/etc/yum.conf --installroot=$LIVE install openssh-clients
  

• You can make any changes you would like to have on your Live CD now or you can do this later also in chroot.
• Copy resolv.conf to the chroot (so yum will work in the chroot)

  cp /etc/resolv.conf $LIVE/etc 
  

• Copy your networking configuration file

  cp /etc/sysconfig/network $LIVE/etc/sysconfig/
  

• You may want to copy other system config files, like

  cp /etc/sysconfig/i18n $LIVE/etc/sysconfig/
  cp /etc/sysconfig/authconfig $LIVE/etc/sysconfig/
  cp /etc/sysconfig/kernel $LIVE/etc/sysconfig/
  cp /etc/sysconfig/clock $LIVE/etc/sysconfig/
  

• Switch to chroot of $LIVE

  umount $LIVE/proc
  chroot $LIVE
  

• Mount /proc in chroot again:

  mount -t proc proc /proc
  

• To leave chroot and unmount /proc in advance, type

  umount /proc
  exit
  

• Since build script version livecd-2.0.0 or newer, no special livecd kernel is required anymore. The standard Scientific Linux kernel can be used. If not yet done, install the kernel in $LIVE:

  yum -c $LIVE/etc/yum.conf --installroot=$LIVE install kernel
  

• Now you have to install the unionfs and squashfs kernel-modules for the installed kernel.
• Install the kernel modules and related packges in chroot.
  
• Starting with kernel version 2.6.9-89.0.9.EL unionfs and squashfs are now part of SL4, just run

  chroot $LIVE
  yum install squashfs kernel-module-squashfs 
  yum install unionfs kernel-module-unionfs
  

• If you run another kernel, you can rebuild squashfs and unionfs RPMS from the SRPMS: http://www.livecd.ethz.ch/download/SRPMS/4x. The usage of rpmbuild is described in the spec files.

• In case of SL5 squashfs is included in the kernel. You only have to install the squashfs-tools, which are part of SL5:

  chroot $LIVE
  yum install squashfs-tools
  

• Aufs (another union file system) seems to be more stable than unionfs. Aufs can be compiled against the SL5 kernel whereas the SL4 kernel is too old. Prebuild aufs RPMs for SL5 kernels can be found here http://www.livecd.ethz.ch/download/RPMS/5x
• Starting with kernel version 2.6.18-128.1.1.el5 aufs is now part of SL5, just run

  yum install aufs
  

  to install aufs and the related kernel module.
• If you run another kernel, you can rebuild aufs RPMS from the SRPMS: http://www.livecd.ethz.ch/download/SRPMS/5x. The usage of rpmbuild for aufs is described in the aufs.spec file.

• Download the latest build scripts (livecd-x.x.tar.gz) from here http://www.livecd.ethz.ch/download/build
• Copy the tarball to chroot, for example into the folder build

  mkdir $LIVE/build
  cp livecd-x.x.x.tar.gz $LIVE/build
  

• chroot into the image

  chroot $LIVE 
  

• Unpack the scripts in chroot

  cd /build
  tar xfvz livecd-x.x.x.tar.gz
  

• Change to the livecd build script directory

  cd /build/livecd-x.x.x
  

• Change the configuration in the file livecd.conf:

  vi livecd.conf
  

• You have to specify the kernel version that you have installed inside chroot environement. Assuming you kernel is 2.6.9-42.0.3.EL change in livecd.conf:

  KERNEL="2.6.9-42.0.3.EL"
  

• And you have to define the OS_RELEASE in livecd.conf. For SL4, RHEL4, CentOS4 set

  OS_RELEASE=4
  

  For SL5, RHEL5, CentOS5 set

  OS_RELEASE=5
  

• Please note: Before livecd-2.9.0 you had to define the OS_RELEASE with an option passing to build-livecd.sh, see:

  build-livecd.sh -h
  

• In addition you can set the OS update release. For example for SL 5.3 set

  OS_UPDATE=3
  

• You can define more in livecd.conf, For example, in order to set the default runlevel of your LiveCD to 3, change in livecd.conf

  RUNLEVEL=3
  

• Or if you want to add some extra boot parameters

  EXTRA_BOOT_OPTIONS="kb=us nopasswd"
  

• Now run the build script 
  WARNING: Always run the scripts in the chroot environment !!

  ./build-livecd.sh 
  

• The creation of the compressed images, particularly usr.mo, will take some time.
• If everything goes well, you should get the LiveCD ISO created in /tmp/livecd.iso or $LIVE/tmp/livecd.iso, respectively.
• For more information about the build scripts see also the README file provided within the tarball.

• You can burn this ISO image to a CD or DVD ROM. However, it is much easier to test it with qemu
• For example get qemu from here: http://dag.wieers.com/packages/qemu. Take the rpm for el4.
• How to run qemu (see also man qemu):

  qemu -m 256 -cdrom livecd.iso
  qemu -m 256 -full-screen -cdrom livecd.iso
  

• Escape full screen in qemu with ALT+CTRL+f
• Or alternatively you can use VMware Player or VMware Server.