5. Including the updates

5.3.1.1. Regenerating the hdlist file

When installing from the CD, the installation program on the CD relies on the file RedHat/base/hdlist describing what RPM packages are available on the CD. The hdlist file can be generated by the program misc/src/install/genhdlist. This program must be run with the absolute path to the root of the distribution as the only argument. Here is the updateHdlist script which calls that program (from version 1.34 of this howto):

#!/bin/bash RHVERSION=6.1 ARCH=i386 echo generating hdlist... RHROOT=/home/luigi/tmp/redhat-${RHVERSION} GENHDDIR=${RHROOT}/${ARCH}/misc/src/anaconda/utils chmod u+x ${GENHDDIR}/genhdlist chmod 644 ${RHROOT}/${ARCH}/RedHat/base/hdlist ${GENHDDIR}/genhdlist ${RHROOT}/${ARCH} || echo "*** GENHDLIST FAILED ***" exit 0

	Important note for RedHat < 6.1
	The installation in RedHat 6.1 is completely changed from earlier versions, and RedHat has introduced anaconda. The genhdlist program is now found in a different place, so in the script above, we used GENHDDIR=${RHROOT}/${ARCH}/misc/src/anaconda/utils while for releases up to (and including) 6.0 that line should read GENHDDIR=${RHROOT}/${ARCH}/misc/src/install

In some cases, genhdlist fails to run, because the executable is not statically linked. In such a case, you can add a new line ${RHROOT}/${ARCH}/RedHat/instimage/usr/lib in /etc/ld.so.conf and run ldconfig -v.

Another solution is to recompile genhdlist. The following modification to the updateHdlist script worked under RedHat 5.2:

#!/bin/bash RHVERSION=6.1 ARCH=i386 RHROOT=/misc/redhat/redhat-${RHVERSION} GENHDDIR=${RHROOT}/${ARCH}/misc/src/anaconda/utils echo Compiling genhdlist... sed -e 's/FD_t/int/' \ -e 's/fdOpen/open/' \ -e 's/fdClose/close/' \ -e 's/fdFileno//' < ${GENHDDIR}/genhdlist.c > /tmp/genhdlist.c cc -o /tmp/genhdlist -I/usr/include/rpm /tmp/genhdlist.c -lrpm -lz echo generating hdlist... chmod 644 ${RHROOT}/${ARCH}/RedHat/base/hdlist /tmp/genhdlist ${RHROOT}/${ARCH} || echo "*** GENHDLIST FAILED ***" exit 0

In this version of the script, a copy of the C source of genhdlist.c is piped through sed to create a copy in /tmp that will compile under RedHat 5.2. This version of genhdlist is then used to create the hdlist file

Important note for RedHat 5.2

As distributed with RedHat version 5.2 and earlier, genhdlist CRASHES if there are files in the RedHat/RPMS directory which are not RPM files! This causes problems, because in the 5.2 distribution, there are a couple of non-RPM files named ls-lR and ls-lR.gz in RedHat/RPMS. Therefore, you must remove all non-RPM files from the directory. Alternatively, you can apply the patch genhdlist.c.diff to misc/src/install/genhdlist.c and do a make. The patch will cause genhdlist to ignore any non-RPM files.

5.3.1.2. Creating the CD iso image

You'll need to create an image file which will be written to the CD. This file will be 500Mb or more so find a partition with enough free space. You may need to be root to use mount and cdrecord. Here you will prepare the iso image of the bootable CD to be burned. It is actually, not strictly necessary, to create a bootable CD, because you could use a boot floppy instead of it, but it's definitely a nifty feature (and makes your disc more similar in behaviour to the original one). These are the commands I use to complete the task:

$ mkdir /images-destination-dir $ mkisofs -r -J -T -v -V "Red Hat 6.1 (Hedwig)" \ -c boot.cat -b images/boot.img \ -o /images-destination-dir/i386-disc.iso .

This is needed to burn the (bootable) disc and is executed from the top level directory of the distribution. The /images-destination-dir directory is the container for the iso image you are generating, and it must exist (obviously) before starting the procedure. In the following table you can read a brief explanation of the various options and their meanings (most of it was extracted from the mkisofs man page).

You will find details of how to burn the image on a media in Burning the CD. The mkisofs and cdrecord steps can be executed by means of a graphical frontend like X-CD-Roast which should currently support the creation of bootable CDs (I've never done it, so don't expect me to give you any explanation).

5.3.3.1. Preliminary operations on the main tree

Some of the scripts included in the anaconda-runtime package need the main tree to be moved in a subdirectory named like the architecture we are building for (so i386/ for me). We will move everything to such directory before starting the procedure and change the invocation of the scripts which don't need this modification.

For redhat 8.0:

$ chmod -R u+w /absolute-path-to-toplevel-dir $ mkdir -p /absolute-path-to-toplevel-dir/i386 $ cd /absolute-path-to-toplevel-dir $ /bin/mv * i386

You should change "/absolute-path-to-toplevel-dir" with the absolute path of the directory where the root of your local copy of the distribution is located (maybe somewhere on some hard drive). You will get an error, from the execution of the last command, because the i386/ directory cannot be moved under itself, but you don't need to worry about that.

For redhat 7.3:

$ chmod -R u+w /absolute-path-to-toplevel-dir $ mkdir -p /absolute-path-to-toplevel-dir/i386 $ cd /absolute-path-to-toplevel-dir $ for i in `ls` ; do [ $i != "SRPMS" -a $i != i386 ] && /bin/mv $i i386 ; done

You shouldn't receive any error message this time from the last command (hopefully).

5.3.3.2. Regenerating the hdlist and hdlist2 files

This is done by means of the following two commands with the help of the genhdlist program.

$ /usr/lib/anaconda-runtime/genhdlist /absolute-path-to-toplevel-dir/i386 $ chmod 644 /absolute-path-to-toplevel-dir/i386/RedHat/base/hdlist{,2}

Once again, "/absolute-path-to-toplevel-dir" is the absolute path of the directory where the root of your local copy of the distribution is located. The second command is needed to make sure the correct permissions are set for the file. You should already have an idea of what these files are about if you have read through The Redhat directory.

5.3.3.3. Update the comps.xml file

In Redhat Linux 8.0 the format of the comps file has completely changed and it's now based on XML. It provides much more flexibility and ease of customization as you can read in The comps file. If you have modified or intend to modify the list of the installed packages, you need to complete this step. This, in turn, implies having the comps-8.0.tar.gz package including the master comps file found on the Redhat website and the comps-extras rpm package installed. Follow these steps (only fo Redhat 8.0):

$ cd /some-dir-of-your-choice $ tar xzvf /path-to-comps-8.0.tar.gz/comps-8.0.tar.gz $ cd comps $ make $ cat comps-milan.xml |sed 's!</comps>!!g' >comps-tmp.xml $ /usr/share/comps-extras/getfullcomps.py comps.xml \ /absolute-path-to-toplevel-dir i386 >> comps-tmp.xml $ echo '</comps>' >> comps-tmp.xml $ cp comps-tmp.xml /absolute-path-to-toplevel-dir/i386/RedHat/base/comps.xml

Beside "/absolute-path-to-toplevel-dir", you should take care of assigning valid names to "/some-dir-of-your-choice" and "/path-to-comps-8.0.tar.gz". The rest of the commands can be just copied.

Before issuing the make command, you should modify the file comps-milan.xml.in using your favourite text editor and following the guidelines and the suggestions found in The comps file and on the anaconda comps section of the Redhat website.

The script presented in the last section will execute all the steps needed after the make command, using the COMPSFILE variable to find the comps-milan.xml file (it doesn't need to have that name, I'm just using the original name, but you can change it if you want).

If you are using Redhat 7.3, the comps file (have you noticed the different name...) is a textual file with a completely different syntax described in some more detail in The comps file. In this case, the only necessary operations are modifying the file to suit your needs and copying it to the RedHat/base/comps file in the main tree overwriting the original one.

5.3.3.4. Rebuilding the installer

This will rebuild the anaconda installer in your local copy of the distribution using your updated packages.

$ /usr/lib/anaconda-runtime/buildinstall \ --pkgorder /absolute-path-to-toplevel-dir/pkgorder.txt \ --comp dist-8.0 --version 8.0 --release "Redhat 8.0 (Psyche)" \ /absolute-path-to-toplevel-dir/i386

Where, once again, "/absolute-path-to-toplevel-dir" is the directory where the root of your local copy of the distribution is located.

For Redhat 7.3, the procedure is pretty much the same:

$ /usr/lib/anaconda-runtime/buildinstall \ --pkgorder /absolute-path-to-toplevel-dir/pkgorder.txt \ --comp dist-7.3 --version 7.3 /absolute-path-to-toplevel-dir/i386

The absence of the (mandatory in 8.0) --release option is the only noticeable difference.

5.3.3.5. Split the distribution

This will create five directories, each one corresponding to a different CD and will put in them hard links to the real files contained in your local copy of the distribution.

This will not work at all for Redhat 7.3 if you don't use the modified version of the splitdistro script reported in the next paragraph. For Redhat 8.0, a modified version of splitdistro is provided mainly because even if the problems in the previous script were fixed, the execution now fails if there are not enough packages to fill all the CDs (the first four completely and the last one even just partly).

            $ $/usr/lib/anaconda-runtime/splitdistro  \
              --fileorder /absolute-path-to-toplevel-dir/pkgorder.txt  --release \
                "Redhat 8.0 (Psyche)"  /absolute-path-to-toplevel-dir  i386 
          

For Redhat 7.3 the version of the splitdistro7.3 (python) script used was extracted from the anaconda-runtime 7.3.7 package and modified by me. You should sustitute it to the original one (maybe after copying the latter) named /usr/lib/anaconda-runtime/splitdistro.

The only modification (apart from some small fixes), the script went through, is a change in its behaviour if the SRPMS directory is not found (doesn't terminate, but generate the CDs without source packages).

For Redhat 8.0 the version of the splitdistro8.0 (python) script used was extracted from the anaconda-runtime 8.0.4 package and modified once again by me to obtain some improvements I felt the need for. You should sustitute it to the original one (maybe after copying the latter somewhere) named /usr/lib/anaconda-runtime/splitdistro. Anyway, the original one works well, if you want to build a distribution which has all the SRPMS packages (so to fill all the 5 CDs otherwise the script will fail).

The only modification the script went through is a change in its behaviour if the SRPMS directory is not found (doesn't terminate failing, but generates the CDs without source packages) or there is one CD which hasn't any package on it (instead of failing, generates an empty directory).

5.3.3.6. Regenerating the hdlist and hdlist2 files

This is needed to recreate the hdlist and hdlist2 files, using some of the informations obtained in the previous steps. There are no differences between 7.3 and 8.0 for this execution of the program The command to issue is the following:

$ /usr/lib/anaconda-runtime/genhdlist \ --fileorder /absolute-path-to-toplevel-dir/pkgorder.txt --withnumbers \ /absolute-path-to-toplevel-dir/i386-disc[1-3]

As you can see, there are two new options passed to the program, if you remember the first run of it. The first one, --fileorder, tells genhdlist to use the file pkgorder.txt we generated in the second step (rebuild the installer). This file keeps informations on how the packages were split on the different CDs and is used by the installer to determine in which order the packages should be installed. Basically, if you avoid using it, you will (probably) end up swapping the various CDs many times during the installation. The --withnumbers option is needed to associate a CD number to every package (as you can see, a wildcard indicating the first 3 iso images is used).

5.3.3.7. Generating the iso images

Here you will prepare the 5 iso images to be burned on the actual CDs. There are two different commands to be used for the first disc and for the rest of them. This is due to the need of obtaining a first CD which is bootable. This is actually, not strictly necessary, because you could use a boot floppy instead of it, but it's definitely a nifty feature (and makes your discs more similar in behaviour to the original ones). These are the commands I use to complete the task:

$ mkdir /images-destination-dir $ mkisofs -r -J -T -v -V "Red Hat 8.0 (Psyche) disc 1" \ -c isolinux/boot.cat -b isolinux/isolinux.bin -no-emul-boot \ -boot-load-size 4 -boot-info-table -o /images-destination-dir/i386-disc1.iso .

This is needed to burn the first (bootable) disc for RedHat 8.0 (with no floppy emulation) and is executed from the top level directory of the distribution. The /images-destination-dir directory is the container for the five iso images you are generating, and it must exist before starting the procedure.

$ mkdir /images-destination-dir $ mkisofs -r -J -T -v -V "Red Hat 7.3 (Valhalla) disc 1" \ -c boot.cat -b dosutils/autoboot/boot.img \ -o /images-destination-dir/i386-disc1.iso .

This is needed to burn the first (bootable) disc on 7.3 and is executed from the top level directory of the distribution (this time with floppy emulation).

The rest of the images can be written by means of this "for" loop

$ for i in `echo 2 3 4 5` ; do mkisofs -r -J -T -v \ -V "Red Hat 8.0 (Psyche) disc ${i}" \ -o /images-destination-dir/i386-disc${i}.iso . ; done

The loop just presented will prepare the last four images giving them the correct numbers. As you can see, there are just two missing options from the first run, and, as you can guess, they are needed only to create a bootable CD. In Creating the CD iso image, you can read a brief explanation of the various options and their meanings (most of it was extracted from the man page).

5.3.3.8. Implant and check the md5 signatures in the iso images

This is actually an optional step but it permits the use of the "checkmedia" option to verify the CDs signatures before installing them, so to guarantee their correctness.

The following commands permit to inject and verify an md5 signature on an iso image:

$ /usr/lib/anaconda/implantisomd5 iso-image $ /usr/lib/anaconda/checkisomd5 iso-image

After completing all these steps, we will find ourselves with the five CD images to burn. Considering that typing all this stuff is a bit time consuming, in the next section is presented a script, which will complete all of the listed operations in a single run (do not forget to configure the parameters properly).

5.3.3.9. Putting all the steps together

The updateBuild.sh script will execute all the steps needed to rebuild the distribution CDs for RedHat 7.3 or 8.0 in a single run (as root). Before using this script you have to configure the rhcd.conf configuration file after exporting a RHCDPATH variable pointing to the directory where this file is. If you want to include a modified comps.xml (or comps) file in your CDs as explained in The comps file, you should copy it into the location defined by means of the COMPSFILE variable now (before executing the script). Don't forget to add the modified splitdistro script to the /usr/lib/anaconda-runtime directory if you need it.

# export RHCDPATH=/home/luigi/tmp/rhcd-scripts # sh updateBuild.sh