Burning a RedHat CD mini-HOWTO

Burning a RedHat CD mini-HOWTO
Morten Kjeldgaard, [email protected] and Peter von der Ah�,
[email protected]
v1.18, 27 December 1998

This document describes how to make your own CDs from the Red Hat
Linux distribution equivalent to the ones commercially available from
Red Hat. The structure of the distribution is described, as well as
the procedure needed to include updated RPMS into the distribution.
Prerequisites are a good network connection, and a CD-writer.
______________________________________________________________________

Table of Contents

1. Introduction

2. Anatomy of the Red Hat FTP site

2.1 The top level directory
2.2 The "RedHat" directory -- the core of the distribution

3. RPM packages

4. Obtaining your local copy of the distribution

5. Incorporating the updates

5.1 Correcting the file protection modes
5.2 Replacing the updated RPMS
5.3 Generating a new hdlist file
5.3.1 Important note for RedHat 5.2

6. At last: burning the CD

6.1 Creating a bootable CD
6.1.1 Create disk image
6.1.2 Test the image
6.1.3 Burn the disk

7. Installing from the CD

8. This document...

8.1 Related documentation
8.2 Acknowledgements

9. DISCLAIMER

______________________________________________________________________

1. Introduction

There may be several reasons for making your own CD. Perhaps you're a
cheapskate and want to save the $50 cost of the Red Hat distribution
<http://www.redhat.com/>. Or, perhaps you want a distribution CD
containing the latest distribution with all current updates. This is
highly relevant, because after each major release of the Red Hat
distribution, there have been loads of updates, several of which are
security related. Just take a look at the updates/00README.errata
<ftp://ftp.redhat.com/pub/redhat/redhat-5.1/updates/00README.errata>
file. A specific errata sheet also exists for each supported
platform. See for example the Intel errata sheet
<ftp://ftp.redhat.com/pub/redhat/updates/5.1/i386/00README.errata>

2. Anatomy of the Red Hat FTP site

In the spirit of the Linux community, Red Hat Software has made
available their Linux distributions for several platforms on their FTP
site. These are all available from the top distribution directory.

2.1. The top level directory

The toplevel directory for RedHat Linux release 5.1
(pub/redhat/redhat-5.1 <ftp://ftp.redhat.com/pub/redhat/redhat-5.1/>)
contains distributions for the different platforms, and a directory
containing updates and corrections to program packages that have been
published since the release.

SRPMS/ alpha/ i386/ sparc/ updates/

In this document, we use the i386 distribution as an example. The
procedure given in this document is likely to work on all platforms
supported by Red Hat (Alpha, SPARC, ppc, etc.), but we have only
tested it on the i386 platform (the authors would be most interested
in additional information). The root of the i386 directory looks like
this:

-rw-r--r-- 8 ftpuser ftpusers 19686 May 27 1997 COPYING
-rw-r--r-- 1 ftpuser ftpusers 3023 May 7 09:58 README
-rw-r--r-- 10 ftpuser ftpusers 2751 Sep 18 1997 RPM-PGP-KEY
drwxr-xr-x 5 ftpuser ftpusers 96 Jul 15 08:34 RedHat/
drwxr-xr-x 5 ftpuser ftpusers 8192 Jul 15 08:35 doc/
drwxr-xr-x 5 ftpuser ftpusers 8192 Jul 15 08:35 dosutils/
drwxr-xr-x 5 ftpuser ftpusers 8192 Jul 15 08:33 gnome/
drwxr-xr-x 2 ftpuser ftpusers 96 Jun 7 02:47 images/
drwxr-xr-x 4 ftpuser ftpusers 96 Jun 5 12:24 misc/

The doc directory contains an abundance of information. Most
importantly, the RedHat installation manual can be found in HTML
format in the directory doc/rhmanual/manual/
<ftp://ftp.redhat.com/pub/redhat/redhat-5.1/i386/doc/rhmanual/manual/doc000.htm>.
Next, there is a number of FAQs, and finally, the entire collection of
HOWTOs and mini-HOWTOs.

The images directory contains boot floppy images that must be copied
to a diskette. In the most recent distribution (5.1), there are two
disk images available. The boot image is called boot.img, which is
required when installation is performed directly from a CD-ROM. If
installation from a local hard disk, NFS mounted disk or FTP is
required, the supplementary disk image supp.img might be needed. See
section ``Installing from the CD'' and references therein for details.

The misc directory contains source and executables of a number of
programs needed for the installation.

2.2. The "RedHat" directory -- the core of the distribution

The most important part of the directory tree is rooted in the RedHat
directory:

drwxr-xr-x 2 ftpuser ftpusers 24576 Jul 15 08:35 RPMS/
drwxr-xr-x 2 ftpuser ftpusers 8192 Jul 15 08:32 base/
-rw-rw-rw- 59 ftpuser ftpusers 0 Aug 15 14:21 i386
drwxr-xr-x 4 ftpuser ftpusers 96 Jun 5 12:24 instimage/

The RPMS directory contains the major part of the Red Hat distribution
consisting of a set of RPM (Redhat Package Manager) files. An RPM
package typically contains binary executables, along with relevant
configuration files and documentation. See the section ``RPM
packages'' for more information.

The base directory holds different book-keeping files needed during
the installation process, e.g. the comps file, which defines the
components (groups of packages) used during the "Choose packages to
install" phase. Another important file in the base directory is the
hdlist file containing most of the header fields from all the RPMs in
the RPMS directory.

This means that all the interdependencies among RPM packages can be
determined just by reading hdlist without having to read all the RPM
packages which is quite convenient especially during FTP installs.

Another use of hdlist is mapping package names to file name, eg. perl
to perl-5.004-6.i386.rpm. This means that if you want to incorporate
updates from RedHat (see section ``Incorporating the updates'') or add
your own packages to the RPMS directory, you need to update hdlist.
This is descriped later in ``Generating a new hdlist file''.

The instimage directory contains a bare-bones live file system with a
number of programs and shared libraries needed during the installation
procedure.

3. RPM packages

The major part of the Red Hat distribution consists of a set of RPM
(Redhat Package Manager) files. An RPM package typically contains
binary executables, along with relevant configuration files and
documentation. The rpm <http://www.rpm.org> program is a powerful
package manager, which can be used to install, query, verify, update,
erase and build software packages in the RPM format. Rpm convieniently
maintains a database of all the software packages it has installed, so
information on the installed software is available at any time.

The binary RPM files in the distribution have been built on a system
running the distribution itself. This is important, because most of
the programs in the packages rely on shared libraries. From RedHat
version 5.0, the new version 2 of the GNU standard C library (which is
64-bit clean) has been used. This version of the library is commonly
referred to as glibc or in Linux: libc 6. All executables in the
distribution have been linked against this library. If you attempt to
install binary files from a different distribution, chances are that
they will not work, unless you install the libc5 package for backwards
compability.

The names of the RPM packages contain the suffix .arch.rpm, where arch
is the architechture, having the value i386 for Intel platform
binaries. The packages you install must match the versions of the
shared libraries available on the machine. The rpm
<http://www.rpm.org> program is usually quite good at ensuring that
this is indeed the case, however, there are ways around this check,
and you should be sure that you know what you are doing if you force
installation of packages this way. However, using the RedHat
installation boot disk, it is ensured that the correct set of RPM
packages are installed on the machine.

If you discover an RPM package that was not installed on your system
during the installation process, don't despair. At any time, you may
(as root) install RPM packages, for example:

rpm --install WindowMaker-0.18-1b.i386.rpm

You can even install directly from the Internet, if you know the URL
of an RPM package:

rpm --install ftp://rufus.w3.org/redhat-contrib/noarch/mirror-2.9-2.noarch.rpm

Another version of the RPM packages contain the original sources used
to build the binaries. These packages have the suffix .src.rpm and are
situated in the SRPMS directory. These packages are not needed on the
installation CD, and in fact, there is not even enough disk space on
an 74 minute burnable CD to accomodate them. Of course, you can make a
separate CD with the SRPMS.

4. Obtaining your local copy of the distribution

You need a copy of the distribution on a writable disk which is
accessible from the computer having the CD writer (duh!). If you want
to incorporate the latest updates, this directory should (also) be
accessible from from a Linux machine, either from a local disk, an NFS
mounted disk on a different computer, or a JAZ disk.

You could copy the distribution from a RedHat CD, or you could get it
via FTP. If you choose to use FTP, the best way to get a correct copy
of the distribution is to use the mirror package.

Mirror is a sophisticated perl script that compares the content of a
directory on a remote site with a local directory. It will use FTP to
fetch the files that are on the remote site but not the local site,
and delete files on the local site that are not on the remote site.
The mirror program is configured with a configuration file. The
mirror package is available as an RPM from rufus.w3.org
<http://rufus.w3.org/linux/RPM/mirror.html>.

Make your local copy mirror.redhat of the mirror configuration file,
and edit the relevant fields at the top of the file. After the default
section, define these packages:

package=updates
site=ftp.sunsite.auc.dk
exclude_patt=(alpha/|sparc/)
remote_dir=/disk1/ftp.redhat.com/pub/redhat/redhat-5.1/updates
local_dir=/jaz/redhat-5.1/updates

package=dist
site=ftp.sunsite.auc.dk
exclude_patt=(alpha/|sparc/)
remote_dir=/disk1/ftp.redhat.com/pub/redhat/redhat-5.1/i386
local_dir=/jaz/redhat-5.1/i386

The following command will download a copy of the entire RedHat tree
on your local disk. *Think* before you do this, you are about to
transfer approximately 350Mb of data.

mirror -pdist mirror.redhat

This will mirror the Red Hat FTP site on your local disk. The content
of a Red Hat distribution does not change between releases, so you
only need to download this package ONCE. All changes to the
distribution are in the updates directory. Thus, if you want to keep
an up-to-date mirror of the Red Hat distribution, you only need to
keep the updates directory current. This is done using the command

mirror -pupdates mirror.redhat

You can run this regularly, say, once a week, through a cron script.
The RedHat distribution is available on a great number of FTP servers
around the world, which are updated daily from the master site at
<ftp://ftp.redhat.com/pub>. You should choose an FTP site close to
you, see the RedHat FAQ
<http://www.redhat.com/support/docs/rhl/RedHat-FAQ/RedHat-
FAQ-12.html#ss12.1>

5. Incorporating the updates

To incorporate the updates, you need write access to the distribution
directory from a Linux machine, with a working version of rpm
<http://www.rpm.org> installed. There are three steps involved:

1. Correct the file protection modes.

2. Replace updated RPMs.

3. Generate the hdlist file

If you maintain a mirror of the updates directory, you can at any time
produce a CD including the current updates by repeating these steps.

5.1. Correcting the file protection modes

During the installation process, some programs are run directly off
the CD. Unfortunately, the FTP program does not always preserve the
protection modes of the files and directories that are copied.
Therefore, it is necessary to make sure that execute permission is
given to programs, shell scripts and shared libraries, before the
directory is burned on the CD. This is done by running the updatePerm
script on your local copy of the distribution:

______________________________________________________________________
#!/bin/bash

RHVERSION=5.1

LIST=/tmp/er3hd3w25
CDDIR=/jaz/redhat-${RHVERSION}

# Find all directories, and make sure they have +x permission
find $CDDIR -type d -exec chmod -c 755 {} \;

# Find all files that are executables, shell or perl scripts
find $CDDIR -type f | file -f - | grep -v RPM \
| egrep -i 'executable|perl|bourne|shell' | cut -f1 -d: > $LIST

# Find shared libraries
find $CDDIR -name \*.so >> $LIST

# Make them executable
while read file
do
if [ ! -x $file ] ; then
chmod -c 755 $file
fi
done < $LIST

/bin/rm $LIST

exit 0
______________________________________________________________________

5.2. Replacing the updated RPMS

The following script called updateCD copies all files from the update
directory to the RPMS directory. The script uses some nifty rpm tricks
to determine what packages in the updates directory are more recent.
Older packages are moved to the ${OLD} directory.

______________________________________________________________________
#! /bin/bash
# This script updates rpms in a RedHat distribution found in $RPMDIR.
# The old rpms will be placed in $OLDDIR.
# The new rpms should be located in $UPDDIR.
# The architechture is $ARCH.

RHVERSION=5.1
ARCH=i386

CDDIR=/jaz/redhat-${RHVERSION}
RPMDIR=${CDDIR}/${ARCH}/RedHat/RPMS
UPDDIR=${CDDIR}/updates/${ARCH}
OLDDIR=${CDDIR}/old

if [ ! -d $OLDDIR ] ; then
echo making directory $OLDDIR
mkdir $OLDDIR
fi

allow_null_glob_expansion=1

for rpm in ${UPDDIR}/*.rpm ; do
NAME=`rpm --queryformat "%{NAME}" -qp $rpm`
unset OLDNAME
for oldrpm in ${RPMDIR}/${NAME}*.rpm ; do
if [ `rpm --queryformat "%{NAME}" -qp $oldrpm` = "$NAME" ]; then
OLDNAME=$oldrpm;
break
fi
done
if [ -z "$OLDNAME" ]; then
echo $NAME is new
cp -pv $rpm $RPMDIR
else
if [ `basename $rpm` != `basename $OLDNAME` ]; then
mv $OLDNAME $OLDDIR
cp -pv $rpm $RPMDIR
fi
fi
done

# Copy new boot image files to the right place...
for newfile in ${UPDDIR}/images/* ; do
file=${CDDIR}$/${ARCH}/images/$(basename ${newfile})
if [ $newfile -nt $file ] ; then
cp -pv $newfile $file
fi
done

exit 0
______________________________________________________________________

5.3. Generating a new 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 root
name of the distribution as the only argument. Here is the
updateHdlist script which calls that program:

______________________________________________________________________
#!/bin/bash

RHVERSION=5.1
ARCH=i386

echo generating hdlist...
CDDIR=/jaz/redhat-${RHVERSION}
GENHDDIR=${CDDIR}/${ARCH}/misc/src/install

chmod u+x ${GENHDDIR}/genhdlist
chmod 644 ${CDDIR}/${ARCH}/RedHat/base/hdlist
${GENHDDIR}/genhdlist ${CDDIR}/${ARCH} || echo "*** GENHDLIST FAILED ***"

exit 0
______________________________________________________________________

NOTE: After having incorporated the updates in the main RedHat/RPMS
directory, your copy of the distribution is no longer a mirror of the
Red Hat distribution site. Actually, it is more up-to-date! Therefore,
if you attempt to mirror the distribution, older versions of the RPM's
that have been updated will be downloaded once more, and the updates
deleted.

5.3.1. 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 following patch to
misc/src/install/genhdlist.c and do a make. The patch will cause
genhdlist to ignore any non-RPM files.

*** genhdlist.c.orig Fri Nov 27 12:08:13 1998
--- genhdlist.c Fri Nov 27 12:08:20 1998
***************
*** 12,23 ****
--- 12,26 ----

#define FILENAME_TAG 1000000

+ /* Not used apparently...
+
int tags[] = { RPMTAG_NAME, RPMTAG_VERSION, RPMTAG_RELEASE, RPMTAG_SERIAL,
RPMTAG_FILENAMES, RPMTAG_FILESIZES, RPMTAG_GROUP,
RPMTAG_REQUIREFLAGS, RPMTAG_REQUIRENAME, RPMTAG_REQUIREVERSION,
RPMTAG_DESCRIPTION, RPMTAG_SUMMARY, RPMTAG_PROVIDES,
RPMTAG_SIZE, RPMTAG_OBSOLETES };
int numTags = sizeof(tags) / sizeof(int);
+ */

int main(int argc, char ** argv) {
char buf[300];
***************
*** 26,34 ****
--- 29,39 ----
struct dirent * ent;
int fd, rc, isSource;
Header h;
+ /* not used
int count, type;
int i;
void * ptr;
+ */

if (argc != 2) {
fprintf(stderr, "usage: genhdlist <dir>\n");
***************
*** 74,79 ****
--- 79,85 ----

rc = rpmReadPackageHeader(fd, , , NULL, NULL);

+ if (!rc) {
headerRemoveEntry(h, RPMTAG_POSTIN);
headerRemoveEntry(h, RPMTAG_POSTUN);
headerRemoveEntry(h, RPMTAG_PREIN);
***************
*** 110,115 ****
--- 116,122 ----
headerWrite(outfd, h, HEADER_MAGIC_YES);
headerFree(h);
close(fd);
+ }
}

errno = 0;

6. At last: burning the CD

As we assume that you have a working CD-writer on your system, and you
know how to use it, we wont go into much detail about burning the CD.
If you are burning your CD on a Linux system, you can install the
excellent XCDroast <http://www.fh-muenchen.de/rz/xcdroast> package.
In XCDRoast, switch on the Rock Ridge extensions, and the creation of
a TRANS.TBL file.

Make sure the top directory of the CD contains at least the following
files and directories:

COPYING RPM-PGP-KEY README RedHat/

The following directories might come in handy:

doc/ gnome/ misc/ dosutils/ images/

6.1. Creating a bootable CD

(This section, thanks to Dawn Endico [email protected]). Since
XCDroast doesn't support creation of bootable disks you'll need to use
other tools, for example mkisofs
<ftp://tsx-11.mit.edu/pub/linux/packages/mkisofs/> and cdrecord
<http://www.fokus.gmd.de/research/cc/glone/employees/joerg.schilling/private/cdrecord.html>.
Get the latest RPMs for these packages from
<ftp://contrib.redhat.com>. 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 and change the path for redhat.img in
the following commands if necessary. You may need to be root to use
mount and cdrecord.

6.1.1. Create disk image

Change directory to the place in your mirror that will be the root
directory of the cd. For instance, redhat-5.2/i386.

mkisofs -v -r -T -J -V "Red Hat 5.2" -b images/boot.img -c misc/boot/boot.cat -o /tmp/redhat.img .

6.1.2. Test the image

If you're paranoid you can test your new disk image by mounting it. If
you forgot to fix the file permissions or set the rock ridge
extensions then the error will be obvious here since the file names
and directory structure will be wrong.
mount -t iso9660 -o ro,loop=/dev/loop0 /tmp/redhat.img /mnt/cdrom

When you're done, don't forget to unmount it.

umount /mnt/cdrom

6.1.3. Burn the disk

Be sure to set the correct speed for your device. This command is for
a 4X CDR. You may have a 1X or 2X drive.

cdrecord -v speed=4 dev=0,0 /tmp/redhat.img

7. Installing from the CD

When installing from the new CD, you first need to create a bootable
installation diskette. IMPORTANT: use a NEW, freshly MS-DOS formatted
diskette! Using an old, worn-out, faulty diskette can result in
strange problems during the installation!

On a Linux system, you can create the diskette using the dd command:

dd if=/mnt/cdrom/images/boot.img of=/dev/fd0 bs=1440k

On a system running DOS or Windows-9x, you need to use the RAWRITE.EXE
program, which is found on the CD in the dosutils directory.

Shut down the machine you want to install (or do a system upgrade) on,
insert the boot diskette and your freshly burned CD, and let the
machine boot from the diskette. For more information on the
installation process, se the documents and the Installation-HOWTO or
the Bootdisk-HOWTO which are on the CD in the doc/HOWTO directory.

8. This document...

The SGML source of the most recent version of this document can be
retrieved from <http://imsb.au.dk/~mok/linux/doc/RedHat-CD.sgml>.

8.1. Related documentation

Ed Schlunder <[email protected]> has written a utility called fix-rhcd to
let you check your Red Hat Linux distribution mirror for matching file
sizes, names, permissions, and symlinks against an "ls -lNR" listing
from the offical Red Hat ftp site. Any permissions that are wrong are
changed to match the ls listing. See the fix-rhcd homepage
<http://www.ajusd.org/~edward/fix-rhcd/>.

8.2. Acknowledgements

Thanks to the following people for valuable input:

� Lars Christensen <[email protected]>

� Thomas Duffy <[email protected]>

� Dawn Endico <[email protected]>

� Seva <[email protected]>

9. DISCLAIMER

While the given information in this document is believed to be
correct, the authors assume no responsibility whatsoever for any
damage to hardware and/or software, or any loss of data resulting from
the procedures outlined in this document.