Building a RedHat root image

The image required to use User-Mode-Linux is just a normal set of executables. These can be extracted from a RedHat distribution using the following proceedure.

There is a script in testing/utils called uml-rhroot.sh. It takes two arguments:

The unpacked distribution will take approximately 133Mb. You will want to locate this on the same partition as your intended root trees for your User-Mode-Linux's as this will permit hard links to be used, saving disk space.

Because the RPM command used uses the chroot(2) system call and needs to change ownership of the files that it creates, it must be run as root. Afterward, you should chown the entire directory to the userid that you will be using for testing (i.e. probably yours). It should eventually suffices to make sure that you can read every file.

You should be able to chroot to this directory and run programs. If you can not at least run ls, then there is a problem.

Expect a couple of errors about install-info.

An example:


Script started on Thu Nov 22 15:51:15 2001
cassidy:/c2/user-mode-linux# df
Filesystem           1k-blocks      Used Available Use% Mounted on
/dev/hda1              3844408   1673528   1975584  46% /
/dev/hda3             12495048   1823404  10036884  16% /home
/dev/hdc1             10325748    805056   8996172   9% /c1
/dev/hdc2             10325780   4815160   4986100  50% /c2
/dev/hdc3             10325780   2972480   6828780  31% /c3
/dev/hdc4              7495084   3059640   4054704  44% /c4
/distros/redhat/7.2/enigma-i386-disc1.iso
                        662072    662072         0 100% /distros/redhat/7.2/disc1
/distros/redhat/7.2/enigma-i386-disc2.iso
                        653740    653740         0 100% /distros/redhat/7.2/disc2
cassidy:/c2/user-mode-linux# /c2/freeswan/sandbox-main/testing/utils/uml-rhroot.sh 
Usage: /c2/freeswan/sandbox-main/testing/utils/uml-rhroot.sh rootdir cdimagedir
cassidy:/c2/user-mode-linux# /c2/freeswan/sandbox-main/testing/utils/uml-rhroot.sh /c2/user-mode-linux/rpm-root/root /distros/redhat/7.2
Assuming RH disc1 at /distros/redhat/7.2/disc1/RedHat/RPMS
        and disc2 at /distros/redhat/7.2/disc2/RedHat/RPMS
/var/tmp/rpm-tmp.99149: /sbin/install-info: No such file or directory
error: execution of %post scriptlet from textutils-2.0.14-2 failed, exit status 127
cat: /proc/mounts: No such file or directory
warning: /var/lib/rpm/Basenames created as /var/lib/rpm/Basenames.rpmnew
warning: /var/lib/rpm/Conflictname created as /var/lib/rpm/Conflictname.rpmnew
warning: /var/lib/rpm/Group created as /var/lib/rpm/Group.rpmnew
warning: /var/lib/rpm/Name created as /var/lib/rpm/Name.rpmnew
warning: /var/lib/rpm/Packages created as /var/lib/rpm/Packages.rpmnew
warning: /var/lib/rpm/Providename created as /var/lib/rpm/Providename.rpmnew
warning: /var/lib/rpm/Requirename created as /var/lib/rpm/Requirename.rpmnew
warning: /var/lib/rpm/Triggername created as /var/lib/rpm/Triggername.rpmnew
You should now chown it to yourself.
cassidy:/c2/user-mode-linux# chown -R mcr rpm-root/root
cassidy:/c2/user-mode-linux# ls rpm-root/root
bin   dev  home    lib	opt   root  tmp  var
boot  etc  initrd  mnt	proc  sbin  usr
cassidy:/c2/user-mode-linux# chroot rpm-root/root
cassidy:/# ls
bin   dev  home    lib  opt   root  tmp  var
boot  etc  initrd  mnt  proc  sbin  usr
cassidy:/# exit
cassidy:/c2/user-mode-linux# exit
Script done on Thu Nov 22 15:54:33 2001